A
Mother's Day is the occasion upon which children stop and say "thank you" to moms all over the world．Homemade cards express gratitude for countless meals cooked，wounds dressed and hugs given． Animal moms， on the other hand， never get any thanks．But animal moms are also 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，which she guards for over two months! When the eggs are ready to hatch, the young crocodiles 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
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．
21. A crocodile mother usually carries her baby to the water ．
A in her pouch B. on her back
C. in her mouth D. by her tail
22. 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
23. According to the passage，what can we know about the koala？
A. A young koala usually stay with its mom for twelve months．
B. The hairless baby lives in the mother's pouch for about half a year．
C. The little koala leaves the pouch at age between four and seven months old．
D. The animal mom needs to be pregnant for over two months before the baby's birth．
