Question 2: For people to be able to survive in groups, individuals had to cooperate with each other, rather than                                   .

A. act alone               B. alone act                         C. act lonely              D. lonely act

Question  1:  The  production  of  different  kinds  of  artificial  materials                   conservation of our natural resources.

A. is                      B. have been                          C. are                         D. were

Question 90: The report says that over five years up to 2013, the                      almost a quarter of the US as land was converted to grow corn for ethanol.

A. crowd                  B. diverse             C. amount            D. abundance

Question 89: Generic medications are just as                  , and much less expensive.

A. effective as brand-name products           B. brand-name products effective

C. brand-name products as effective           D. effectively brand-name products

Question  88:  With  only  two  days  of                        negotiating  time  left,  hope  of progress  was  quickly evaporating at the climate talks.         A. official        B. office          C. officially     D. officious

Question 87: Researchers have discovered 2,000 types of new plants but also say                                are at risk.                            

A. many          B. much          C. the other     D. variety

Question 86: What you say is true, but you could have                                it more tactfully.

A. phrased                   B. talked              C. observed                   D. remarked

Question  85:  Therapists are  currently using  mental imagery  in  the  hope  that                                  in the treatment of cancer.

A. it could use helpfully                                     B. its proof to help

C. it might prove helpful                                    D. its help to aid

Question 84: The                 of life forms on the earth makes zoology an interesting area of study.

A. size                           B. wealth                      C. diversity                   D. crowd

Question 83: We know everything about the newest member of our group; she was very                  

A. expensive                 B. secretive                   C. artistic                      D. reserved