______provided a living for nearly 90 percent of the population of theAmerican colonies.
A.What was farming
B.Farming was
C.Farming was what
D.What farming

Choose the word that best fits the blank space in the following passage.
Is there life on Mars? Many people have wondered about this question. Some writers of science-fiction think of people from Mars (36) _____ little green creatures. Others imagine 'Martians' as monsters with many eyes.
In studying this planet, astronomers have found that life may be possible on Mars. The first indication of this is that Mars has seasons, just like Earth. In other words, Earth's seasons, such as spring or summer, occur on Mars too. Because these seasons exist, it may be possible for (37) _____ and other higher life forms to be found on Mars.
Astronomers also think that perhaps a small (38) _____ of water vapor could be found on Mars. In 1887, an Italian astronomer, Giovanni Schiaparelli, discovered markings on Mars' surface. These markings looked like canals. This finding led astronomers to believe that since water exists on Mars, life forms could exist as well.
However, there are (39) _____ who feel that life on mars is not possible. This is because there is little or no trace of oxygen on the planet. In 1965, the Mariner IV capsule managed to take photographs of the planet. It discovered that the only forms of life found are vegetation like fungi and mosses. (40) _____, people remain fascinated by the idea that there could one day be life on Mars.
A.vegetables
B.vegetation
C.vegetarian
D.veterinary

Choose the word that best fits the blank space in the following passage.
Is there life on Mars? Many people have wondered about this question. Some writers of science-fiction think of people from Mars (36) _____ little green creatures. Others imagine 'Martians' as monsters with many eyes.
In studying this planet, astronomers have found that life may be possible on Mars. The first indication of this is that Mars has seasons, just like Earth. In other words, Earth's seasons, such as spring or summer, occur on Mars too. Because these seasons exist, it may be possible for (37) _____ and other higher life forms to be found on Mars.
Astronomers also think that perhaps a small (38) _____ of water vapor could be found on Mars. In 1887, an Italian astronomer, Giovanni Schiaparelli, discovered markings on Mars' surface. These markings looked like canals. This finding led astronomers to believe that since water exists on Mars, life forms could exist as well.
However, there are (39) _____ who feel that life on mars is not possible. This is because there is little or no trace of oxygen on the planet. In 1965, the Mariner IV capsule managed to take photographs of the planet. It discovered that the only forms of life found are vegetation like fungi and mosses. (40) _____, people remain fascinated by the idea that there could one day be life on Mars.
A.quantity
B.amount
C.portion
D.mass

Choose the word that best fits the blank space in the following passage.
Is there life on Mars? Many people have wondered about this question. Some writers of science-fiction think of people from Mars (36) _____ little green creatures. Others imagine 'Martians' as monsters with many eyes.
In studying this planet, astronomers have found that life may be possible on Mars. The first indication of this is that Mars has seasons, just like Earth. In other words, Earth's seasons, such as spring or summer, occur on Mars too. Because these seasons exist, it may be possible for (37) _____ and other higher life forms to be found on Mars.
Astronomers also think that perhaps a small (38) _____ of water vapor could be found on Mars. In 1887, an Italian astronomer, Giovanni Schiaparelli, discovered markings on Mars' surface. These markings looked like canals. This finding led astronomers to believe that since water exists on Mars, life forms could exist as well.
However, there are (39) _____ who feel that life on mars is not possible. This is because there is little or no trace of oxygen on the planet. In 1965, the Mariner IV capsule managed to take photographs of the planet. It discovered that the only forms of life found are vegetation like fungi and mosses. (40) _____, people remain fascinated by the idea that there could one day be life on Mars.
A.According
B.Nevertheless
C.Thus
D.Consequently

Read the passage carefully, then choose the correct answer.
There is one planet that still fascinates and teases scientists mainly because it doesn't have an atmosphere to obscure observation, yet it is not big enough for sufficiently accurate telescopic observation. The fact that it is also very close to the sun also makes it difficult for astronomers.
However, space telescopes have told us a lot more about Mercury. It is rather similar to Earth's moon and to Mars. There are mountainous areas dotted with craters and large valleys which are uncratered. The moon's valleys have fewer cracks and the ridges are smoother. Mercury's valleys are filled with volcanic rocks, similar to on the moon, yet there is no evidence of volcanoes, even extinct ones, on Mercury, as there is on the both Mars and the moon, and of course here on Earth.
So, scientists presume the valleys on Mercury were caused by different things, that is to say not by volcanoes, but by very large meteorites, which also caused the cracks in the terrain and left the ridges rough and uneven. More and better photos of Mercury are needed to prove what are at present at best only hypotheses.
What is the topic of this passage?
A.The planet, Mercury
B.Observation of planets
C.The Earth's moon
D.Astronomers' difficulties

Read the passage carefully, then choose the correct answer.
There is one planet that still fascinates and teases scientists mainly because it doesn't have an atmosphere to obscure observation, yet it is not big enough for sufficiently accurate telescopic observation. The fact that it is also very close to the sun also makes it difficult for astronomers.
However, space telescopes have told us a lot more about Mercury. It is rather similar to Earth's moon and to Mars. There are mountainous areas dotted with craters and large valleys which are uncratered. The moon's valleys have fewer cracks and the ridges are smoother. Mercury's valleys are filled with volcanic rocks, similar to on the moon, yet there is no evidence of volcanoes, even extinct ones, on Mercury, as there is on the both Mars and the moon, and of course here on Earth.
So, scientists presume the valleys on Mercury were caused by different things, that is to say not by volcanoes, but by very large meteorites, which also caused the cracks in the terrain and left the ridges rough and uneven. More and better photos of Mercury are needed to prove what are at present at best only hypotheses.
Why does Mercury still tease scientists?
A.Because it has an atmosphere which obscures observation
B.Because it is too close to the sun.
C.Because it is too small.
D.Because it is difficult for space probes to get close to.

He teaches ____ piano and ______ violin.
A.the-the
B.a-the
C.the-a
D. -

Choose the word or phrase that best completes the sentence or substitutes for the underlined word or phrase.
No one is indifferent to praise, ______ ?
A.is one
B.isn’t one
C.is he
D.are they

Choose the word or phrase that best completes the sentence or substitutes for the underlined word or phrase.
Somebody has left these socks on the bathroom floor, ______ ?
A.have they
B.haven't they
C.has he
D.hasn't he

Choose the word or phrase that best completes the sentence or substitutes for the underlined word or phrase.
The existence of many stars in the sky ______ us to suspect that there may be life on another planet.
A.lead
B.leads
C.leading
D.have led