问题 填空题

已知圆柱底面半径为4cm,母线长为10cm,则其侧面展开图的面积是______cm2

答案

圆柱的侧面展开图是矩形,它的长为圆柱底面周长8πcm,宽即母线长为10cm,

所以其侧面展开图的面积是8π?10=80πcm2

阅读理解

Animal moms are great moms. You might be surprised at some of these moms.

Octopuses (章鱼)

The mother octopus lays about 50,000 eggs. For about 300 days, she stays with the eggs, cleans them and protects them. She does not leave to feed. However, this animal mom dies as soon as the eggs are hatched (孵化).

Crocodiles(鳄鱼)

A crocodile mother puts a lot of time and effort into raising her babies. She starts by building a nest (巢), which she guards for over two months! When the eggs are ready to hatch, the young crocs call out to their mother, who digs them out and helps them hatch. She then carries them in her mouth down to the water, where she will guard them for several more weeks or months until they learn to hunt on their own.

Bats (蝙蝠)

Bats become moms by hanging head up in a cave, giving birth. Catching the youngster before it can fall to the ground below, she puts it in a pouch (育儿袋). Bat moms may carry babies with them when feeding for the first few days. As the little bats get bigger and heavier, moms help them hang on the wall of their caves and return often to feed them. It continues for about three weeks, until the babies are grown up and able to fly on their own.

Koalas (考拉)

The animal mom gives birth after a pregnancy (怀孕期) of only 35 days. The hairless baby climbs into its mother’s pouch and lives there for another five months. When the little koala is between five and eight months old, it leaves the pouch for short periods of time but returns for safety. Once it is too big to return to the pouch, it will climb onto its mother’s back and ride there until it is about 12 months old.

小题1:Which animal moms die when their babies are born?

A.Octopuses.

B.Crocodiles.

C.Bats.

D.Koalas.小题2:A crocodile mother usually carries her baby to the water _____.

A.in her mouth

B.on her back

C.in her pouch

D.by her tail小题3:A bat mom _____.

A.gives birth by lying in the nest

B.gives birth by hanging in a cave

C.leaves its babies in the pouch for months

D.lets its babies live on their own after birth小题4:How long does the bat mom help to feed her babies?

A.About 3 days

B.About 3 weeks

C.About 13 weeks

D.About 3 months小题5:How long does a young koala usually stay with its mom?

A.35 days.

B.5 months.

C.8 months.

D.12 months.

判断题