What is probably the most important biological problem mentioned in the passage?




A.social and economic deficiencies
B.manipulation of genes
C.genetic engineering misuse
D.environmental pollution

_________ any employee be ill, they must call the office to inform their head of departure.




A.Were
B.Should
C.Had
D.If

The polar bear's ___________depends on its ability to catch fish.




A.survival
B.survive
C.surviving
D.survivor

We are going to build a fence around the field with a view to___________ sheep and cattle.




A.to breeding
B.breed
C.to breed
D.breeding

A.imagine
B.horizon
C.property
D.computer

I should have studied last night, but I was too tired.




A.I couldn't study last night because I was very tired.
B.I studied last night because I had to.
C.I studied last night because I was bored.
D.I tried to study last night, but the homework was too hard.

"Shall I turn on the heater for you?" Lane said to his grandpa.




A.Lane wanted to turn on the heater for his grandpa.
B.Lane offered to turn on the heater for his grandpa.
C.Lane promised to turn on the heater for his grandpa.
D.Lane asked his grandpa to turn on the heater for him.

The word "segregation" may be understood as "____".




A.grouping
B.mixture
C.separation
D.extraction

Ancient education generally focused its efforts on ____.




A.on male learners
B.both sexes
C.female learners
D.young people only

What is the author's purpose in this passage?




A.To conduct a survey of the biologist's role in society
B.To urge biologists to solve the problem of surplus human population
C.To emphasize the biologist's role in solving the world's problems
D.To advise biologists to carry out extensive research into genetic engineering