The subject of the preceding passage was most likely Halley’s
A.childhood
B.work as an astronomer
C.invention of the diving bell
D.many different interests

Halley’s bell was better than its predecessors because it ________ .
A.was bigger
B.provided more air
C.weighed less
D.could rise more quickly

Paragraph 4 of the passage serves mainly to do which of the following?
A.Show the progress of desertification down through history
B.Propose a method for dealing with the desertification problem.
C.Describe one process that leads to desertification
D.Describe the main cause of desertification in one particular area

Look at numbers [1], [2], [3], [4] in paragraph 3 of the passage. Where would the following sentence best fit?
Each furthers the process dramatically, but they act in quite different ways
A.[1]
B.[2]
C.[4]
D.[3]

According to the passage, agriculture furthers desertification through _________- which of the following activities.
A.The repetitive planting of the same crops
B.Irrigation
C.The stripping away of native vegetation
D.Over fertilization

Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information.
A.Most of the vulnerable areas are in transition from desert to arable land; a process that because of human activity and the delicate nature of these areas, always leads to soil loss.
B.Human activity in the transition areas is vulnerable because of the fragile nature of these areas that are neither desert nor arable land because they have suffered damage to the soil
C.Soil loss in the transitional zones is especially severe where human activity is damaging the environment through agriculture which is causing the loss of soil.
D.It is the areas that exist between the deserts and the land that is usable for agriculture that are most at risk because they are susceptible to poor land management methods from human activity which will always result in the loss of soil.

The word “arable” in paragraph 2 is closest in meaning to _________- .
A.cultivatable
B.dry
C.settled
D.populated

Which of the following statements is true about desertification?
A.It has a history as long as that of civilization.
B.It was just as serious in the past as it is today.
C.It is a fairly recent problem.
D.Ancient societies managed the problem well.

Mutualism is a type of symbiosis that occurs when two unlike organisms live together in a state that is mutually beneficial.
A.alike
B.likely
C.similar
D.dislike

Hundreds came to __________ their last respects to the dead president.
A.pay
B.express
C.have
D.indicate