问题 填空题

玉米和菜豆种子萌发过程中子叶的作用分别是______.

答案

玉米种子和菜豆种子的结构是不同的,如表所示:

在种子萌发的过程中,玉米种子的子叶把胚乳里的营养物质转运给胚芽、胚轴、胚根;而菜豆种子在萌发时,子叶里的营养物质直接提供给胚芽、胚轴和胚根利用.

故答案为:前者是从胚乳中吸收养料供给胚的发育,后者直接为胚的发育提供养料.

单项选择题 A型题
阅读理解

When we say that Cambridge is a university town, we do not mean just that it is a town with a university in it. Manchester and Milan have universities, but we do not call them university towns. A university town is one where there is no clear separation between the university buildings and the rest of the city. The university is not just one part of the town; it is all over the town. The heart of Cambridge has its shops, pubs, market-place and so on, but most of it is university-colleges, faculties, libraries, clubs and other places for university staff and students. Students fill the shops, cafes, banks, and churches, making these as well part of the university.,

The town was there first. Two Roman roads crossed there, and there are signs of building before Roman times (earlier than A.D. 43). Cambridge became a center of learning, and the authority of the head of the university was recognized by the king in 1226.

With about 8,250 undergraduates and over2,000 postgraduates, the city is a busy place in “full term” .Undergraduates are not allowed to keep cars in Cambridge, so nearly all of them use bicycles. Don’t try to drive through Cambridge during the five minutes between lectures. Your bicycle must go through a boiling sea of other bicycles hurrying in all directions, if you are in Cambridge at five minutes to the hour any morning of full term, you know that you are in a university town.

小题1:What is called a university town?

A.    A town with a university in it    

B.     B. A university with a town in it.

C.  One where there is no clear separation between a university and a town.

D.    One where there are both a university and a town.

小题2:How many students does Cambridge have?

A.Eight thousand, two hundred and fifty.

B.Two thousand.

C.Ten thousand.

D.More than ten thousand.小题3:Which of the following is NOT mentioned in the passage?

A.the university is all over the town

B.the town came earlier than the university

C.during the five minutes between lectures, your bicycle must go through other bicycles hurrying in all directions.

D.the teachers have many strange ways of making their lectures lively and interesting.小题4:What’s the title of the passage?

A.Cambridge—A University Town.

B.Cambridge – A Centre of Learning

C.Cambridge with Many Students.

D.Cambridge with a Long History