D

The sun is setting on a summer night. At the entrance to a deep, dark cave, a few bats fly out. Then more and more of the small, furry creatures appear. Within a few minutes, a whole river of bats is pouring out of the cave, and they keep coming — millions and millions of them.

       Sound like a scary horror movie? Believe it or not, this scene takes place every night, all summer long, at Bracken Cave in Texas, where 20 million bats fly outside to feed on insects.

      Every March or April, Mexican free-tailed bats migrate up to 1,609 kilometers from their winter home places, like mines, tunnels, hollow trees, and under bridges in Mexico to this cave. Soon after they arrive, each mother gives birth to one baby bat. As many as 500 baby bats live crammed (挤) into one square foot of space, and those bodies create nice warm temperatures to keep them warm and comfortable. With bad sight, how can mother bats recognize their own babies? Their good sense of smell helps them the most.

      When the adult bats leave the cave at night to feed, they eat tons of insects in a single night, including many pests that eat farmers’ crops. And they get rid of mosquitoes, too.

      The cave, quiet in winter, is full of life all summer. The floor of the cave is covered with bugs. Gnats are flying around, and beetles are crawling up your leg when you walk in!

      When twenty million bats fly out of one cave opening, they make a column (柱) so thick that they show up on the radar at the nearby airport. So much for bats being scary!

(1) What is the purpose of the first paragraph?

A. To explain the living habits of bats.

B. To describe what bats look like.

C. To talk about a frightening scene of a film.

D. To introduce the topic of the passage.

(2) Which of the following senses helps mother bats recognize their babies?

A. Touch.	B. Sight.
C. Smell.	D. Taste.

(3) According to the passage, we can learn that ______.

A. the bats living in the cave benefit the local farmers

B. Mexican free-tailed bats prevent other animals living in the cave

C. the large group of Mexican bats sometimes destroy the local radar

D. caves are the places where Mexican bats live all year round

(4) What is the best title of the passage?

A. Life of Mexican free-tailed bats.

B. Amazing Mexican bats of Bracken Cave.

C. A scary scene at Bracken Cave in Texas.

D. Migration of Mexican free-tailed bats.