问题 选择题

油菜植株的结构层次中没有以下哪一项(  )

A.细胞

B.系统

C.组织

D.器官

答案

植物体结构和功能的基本单位是细胞,由细胞再组成组织,构成植物体的主要组织有:保护组织、营养组织、输导组织、机械组织和分生组织.不同的组织再组成器官,植物有六大器官:根、茎、叶、花、果实和种子,由这六大器官直接构成整个绿色开花植物体.可见植物体的结构层次从微观到宏观依次是细胞→组织→器官→植物体,系统是动物的结构层次之一.可见B符合题意.

故选:B

阅读理解

We’ve talked about snails (蜗牛) and their slow move. But much of the time snails don’t move at all. They are in their shells (壳) —sleeping.

Hot sun will dry out a snail’s body. So at the least sign of hot sun, a snail draws its body into his shell. A snail will die in a heavy rain. So when it rains, a snail does the same thing, too. A snail can sleep for as long as it needs to. It spends all the winter months in its shell, asleep.

In the spring the snail wakes up. Its body, about three inches long, comes out from the shell. When hungry, the snail looks for food. Its eyes, at the end of the top feelers (触角), are very weak. But its sense (感觉) of smell is very strong. It helps the snail to find food and the new greens.

A snail’s mouth is no bigger than the point of a pin (大头针). Yet it has 256,000 teeth! The teeth are very small, and you can’t see them. If you put a snail in a hard paper box, it will eat its way out! And if a snail wears out its teeth, it will grow new ones.

小题1: A snail _________.

A.moves more slowly at night

B.has thousands of feet

C.doesn’t move at all  

D.sleeps much of the time小题2: In the sentence “A snail draws its body into its shell”, the word “draw” means _____.

A.to make with a pencil

B.to push

C.to pull

D.to move away小题3: From the story, we know _________.

A.a snail’s shell is very thin

B.a snail can’t see well

C.a snail’s nose is quite short

D.a snail’s body changes in different seasons小题4: A snail goes to sleep when _____.

A.it feels hungry

B.it is put into a paper box

C.spring is coming

D.it rains heavily小题5:Which of the following is wrong?

A.In winter the snail doesn’t eat or move.

B.A snail doesn’t like living under the sun

C.The snail’s teeth can’t be worn out.

D.The snail’s nose helps to find food.

单项选择题 A1/A2型题