简述转塔车床与普通卧式车床在结构上的区别及其加工特点。

阅读理解。

     We are learning English, but how can we learn English well. A student can know a lot about English,

but maybe he can't speak English.

     If you want to know how to swim, you must get into the river. And if you want to be a football

player, you must play football.

     So, you see. You can learn English only by using it. You must listen to your teacher in class.

     You must read your lessons every day. You must speak English to your classmates and you must

write something sometimes. Then one day, you may find your English very good.

1.You know a lot about English but maybe          .

A.you can speak

B.you can study it 

C.you can't study it

D.you can't use it

2.You must get into the river          .

A.to catch a fish

B.to learn how to swim

C.to go boating 

D.to play with water

3.If you want to be a football player, please          .

A.buy a good football 

B.play football

C.watch others play football

D.put your football away

4.If you want to study English well, you must often           .

A.speak English

B.write in English

C.listen to English

D.do all of A.B.C

5.From the passage we know "         ".

A.You know an apple good or not if you eat it

B.You can't do anything if you don't know how to do it

C.You must speak English before you know how to use it

D.Swimming is a good example for you to learn English well

依次填入下列各句横线处的词语，恰当的一项是

（1）三峡两岸＿＿的峰峦、嶙峋的怪石，如绝妙的风景画，给人以丰富的遐思。

（2）新疆人内引外联携手开发的构思正缔结着旷世＿＿：聚四海，连五洲，吞吐八方风云。

（3）著名科学家罗伯特·科尔获得诺贝尔化学奖，不久将去瑞典参加＿＿仪式。

A．突出 因缘 受奖

B．凸出 姻缘 受奖

C．突出 姻缘 授奖

D．凸出 因缘 授奖

关于转基因食品的安全性评价应做到多环节，下面哪些属于转基因食品安全性评价的环节？（）①转基因农作物的研究②转基因农作物的农田试种③转基因农作物的大面积种植④转基因食品的商品化

A.①②

B.①②③

C.②③

D.①②③④

台湾北部种茶之发源甚早。如嘉庆年间即自哪里引入茶的种植？（）

A.安徽

B.河南

C.广东

D.福建

工业铝电解槽的电能消耗量只决定于平均电压。