题目

Animals grow up in different ways. They have lots of lessons to learn. Some animals are born helpless but their mothers protect them. A newborn kangaroo is the size of a bee. She stays in her mother's safe pouch. She doesn't open her eyes for at least five months. A newborn monkey cannot walk. He is carried by his mother.Other baby animals can walk soon after they're born. They learn to run with their mother when danger is near. A baby zebra(斑马)can run an hour after she is born.Some baby animals are born in a place that is safe. Other baby animals are born in the open.  Baby wolves are bo 如图所示为某宾馆的房卡．只有把房卡插入槽中，房间内的灯和插座才能有电．房卡的作用相当于一个________接在干路上．房间里有电灯、电视等用电器，它们是________联的．