问题 单项选择题

线性表是一个______。

A.有限序列,可以为空

B.有限序列,不能为空

C.无限序列,可以为空

D.无限序列,不能为空

答案

参考答案:A

解析: 参见线性表的定义。如果一个非空的数据结构满足下列两个条件:第一,有且只有一个根节点;第二,每一个节点最多有一个前件,也最多有一个后件,则称该数据结构为线性结构。线性结构又称线性表。

阅读理解

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 born in large holes. A baby elephant is born on open, grassy land. Other elephants make a circle(圈)to protect her.  

Animals that drink their mothers’ milk are called mammals. A mother bear’s milk is fatty and rich. Baby bears need lots of fat to keep warm in winter. They have milk for six months. Baby zebras drink milk for six months or more! As baby animals grow they need solid(固体的)food. Baby lions eat what their mother can catch.

小题1:Which baby animals don’t open their eyes for at least five months?

A.Lions.

B.Zebras.

C.Kangaroos.

D.Elephants.小题2:What can’t a baby zebra do an hour after she is born?

A.Drink milk.

B.Walk by herself.

C.Run with her mother.

D.Make a circle to protect herself.小题3:Which of the following is TRUE according to the passage?

A.Baby wolves are born in the open.

B.Newborn lions only eat solid food.

C.Newborn monkeys can walk but can’t jump.

D.Baby bears need lots of fat to keep warm in winter.

单项选择题