"________"．

　　A．sleepy　　　　　　　 　B．inactive

　　C．energetic D．movable

　　解析：选A　词义猜测题。根据第二段最后一句中的"sleeping for around 19.5 hours per day"可知，这种棕色蝙蝠每天会睡大约19.5个小时，据此可以判断，这种蝙蝠整天昏昏欲睡，故A项正确。B项意为"不活跃的"；C项意为"充满活力的"；D项意为"可移动的"。

　　2．Why do little brown bats have a long period of sleep?

　　A．To avoid sunshine.

　　B．To save more energy.

　　C．To relax themselves.

　　D．To wait for their insect food.

　　解析：选B　细节理解题。根据第三段中的"This long period of sleep is thought to be a way of conserving energy and it means brown bats only hunt for a few hours each night"可知，棕色蝙蝠长时间的睡眠可以保存能量，以使它们能在数小时的猎食中保持体能，故B项正确。

　　3．How do dolphins avoid drowning while sleeping?

　　A．By taking extra naps.

　　B．By holding hands or paws.

　　C．By keeping half of their brain alert.

　　D．By breathing through their blowholes.

　　解析：选C　细节理解题。根据第五段第二句中的"dolphins and whales sleep while keeping half of their brain alert (警觉的), so they don't drown"可知，海豚通过保持一半的大脑警觉，以使自己不至于被淹死，故C项正确。

　　4．What do sea otters do in order not to be separated from each other?

　　A．They don't sleep.

　　B．They float on rafts.

　　C．They float in groups.

　　D．They hold hands all the time.

解析：选C　细节理解题。根据最后一段的第一句"While sea otters aren't alert when