题目内容：

    When she was studying to become a scientist, Megan Strauss rode in a small airplane to study giraffes. While a pilot flew over the Serengeti in Tanzania, Africa, the researchers looked down carefully and counted giraffes.

"I am always amazed how easily we can spot warthogs and other small animals, yet we sometimes have trouble seeing giraffes. Giraffes are slender in shape, and they may not throw a good shadow, " says Dr. Strauss, who has since become a wildlife scientist.

The Serengeti is about the size of Vermont, a state in the northeastern US, so the scientists could not study the entire area. Instead, they surveyed three areas where giraffes were studied in the 1970s. As they expected, they saw far fewer of these animals.

To find out if lions had been killing more giraffes in recent years, the team looked at the survival of young giraffes. Lions kill more young giraffes than adults, but the team found no decrease in young giraffes' survival after they are born, compared with the 1970s.

The team then looked at whether too many giraffes were being killed by parasites(寄生虫).The researchers counted parasite eggs in giraffe droppings, and they found too few to harm the giraffe population.

They looked into whether poachers (盗猎者)were killing too many giraffes. Two of the areas they studied are where giraffe meat is sometimes sold in local markets. Poachers catch more adult males than other giraffes. Researchers spotted too few males compared with females in those two areas, a sign of poaching.

When the food supply is short, the environment supports fewer giraffes and the females have fewer young giraffes. A lot of new trees have grown in the Serengeti, but many are a type that giraffes do not like to eat. The researchers found fewer young giraffes today than in the 1970s compared with the number of adult females, a sign that food was in short supply.

Dr. Strauss is working on an environmental education program for Tanzania including books for students. These materials will educate Tanzanians and help them to help giraffes. As knowledge grows and changes are made, they hope the giraffe population will increase.

1.What did Dr. Strauss find while studying giraffes in the Serengeti?

A.It was too costly to study giraffes.

B.It was hard to spot giraffes from the air.

C.The number of giraffes had increased slowly.

D.Giraffes lived in smaller areas than in the 1970s.

2.How did the team study the lion-giraffe relationship?

A.By analyzing giraffe droppings.

B.By comparing young giraffes with adults.

C.By comparing male giraffes and females.

D.By surveying the survival of young giraffes.

3.What is Dr. Strauss doing to help giraffes?

A.She is founding a national park in Tanzania.

B.She is counting giraffes in the entire Serengeti.

C.She is educating students to write about giraffes.

D.She is raising environmental awareness in local people.