All across California, honeybees are flying away from their hives and dying. Empty hives are causing a lot of worry about some important food crops.
Bees give us a lot more than delicious honey. They are pollinators （授 粉 者）—they enable plants to produce the fruits and nuts we enjoy by carrying pollen from one plant or flower to the next. The wind pollinates oats, corn, and wheat, but many other plants (like apple and cherry trees and melon vines) depend on insects, bats, and birds. In the U.S., millions and millions of bees kept by human beekeepers fly around doing a lot of this important work for food crops. “Bees are worth protecting because their work adds so much to our diet,” says Dr. Jeff Pettis of the Bee Research Laboratory.
California’s almond crop alone depends on about half the bees in the country. But now the almond crop and many others could be in trouble with so many bees dying.
Researchers at government and university labs all over the country are trying to figure out why so many bees are dying. However, bees are hard to study. Most die away from the hive, so researchers don’t have dead bodies to examine. And when researchers return to a hive after two weeks, about half the bees they studied on their first visit will be dead, replaced by new ones in the natural life cycle of bees. “It isn’t like studying a large animal like a cow that doesn’t move around much and is easy to find out in the cow field,” says Pettis.
Researchers have some ideas about what could be affecting bee health. They could be sick from poisons widely used to kill insects, or they might not be getting enough good food to stay strong. Also, tiny insects called mites feed on bees. “A virus or bacteria could also be doing the killing.” explains Pettis.
What is the main idea of Paragraph 2?

A．The ways of crops pollinating

B．The importance of bees to food crops.

C．The variety of food crops

D．The protection of honeybees

The reason why bees are hard to study is that ____________.

A．all the bees studied by researchers are often replaced by new bees by beekeepers

B．they never return to hives

C．they are too small to be seen

D．they fly around too much

The almond crop and many others in California could be in trouble because ____

A．many bees are dying

B．researchers have difficulty studying bees

C．there is no rain and the crops can’t be irrigated

D．all the pollinators such insects , birds and bats disappear

According to the passage ,which of the following can’t affect bee health ?

A．Poisons to kill birds.

B．Lack of good food

C．Large birds feeding on insects

D．Some virus.

What can we learn from the article?

A．A large number of bees have died in the hive.

B．Without bees, some foods would disappear from our diet.

C．Only researchers in California want to know what kills bees.

D．Large animals are easier to study than tiny insects.