A. more people have moved to malaria-infected areas

B. mosquitoes have become resistant to pesticides

C. genetically modified mosquitoes still transmit the disease

D. mosquitoes bite as many as 500 million people a year

47. Lanzaro is hopeful that in a few year man can         .

A. start to eliminate malaria                   B. cure parasitic blood diseases

C. prevent mice form transmitting parasites     D. acquire immunity against malaria

48. Lanzaro is confident that scientists can block the transmissions of malaria to humans because         .

A. natural mosquito populations do not change

B. scientists have succeeded with birds and mice

C. foreign genes always go where they are required

D. lab-raised mosquitoes will not be resistant to drugs

49. What is the most difficult part of Lanzaro’s project？

A. Spreading malaria-resistant genes into natural mosquito populations.

B. Raising malaria-resistant mosquitoes.

C. Making genes that block the transmission of malaria.

D. Identifying malaria-resistant genes.

50. According to the passage，a fundamental way to wipe out malaria is to         .

A. develop new malaria-resistant drugs

B. produce effective pesticides to kill mosquitoes

C. change the genetic makeup of mosquitoes

D. remove people from malaria-infected areas

Passage Five

According to Scott Adams，creator of the comic strip（系列漫画）Dilbert，the annual performance review is“one of the most frightening and weakening experiences in every employee’s life. Adam’s stories and comic figures poke fun at the workplace，but his characterization of people’s feelings about the annual performance review has its serious side. Although a recent study of 437 companies indicates that effective annual performance reviews can help raise profits，most employees of those companies hate them.

In theory，annual performance reviews are constructive and positive interactions between managers and employees working together to attain maximum performance and strengthen the organization. In reality，they often create division，undermine morale，and spark anger and jealousy. Thus，although the object of the annual performance review is to improve performance，it often has the opposite result. A programmer at an IT firm was stunned to learn at her annual performance review that she was denied a promotion because she wasn’t a“team player”. What were the data used to make this judgment？She didn’t smile in the company photo.