凤香型白酒以陕西西凤酒为代表。有（）为主，（）为辅的复合香气。

下列物质中哪一个不经NADH氧化呼吸链氧化（）

A.琥珀酸

B.苹果酸

C.异柠檬酸

D.β－羟丁酸

E.谷氨酸

阅读理解。

     In order to know a foreign language thoroughly (完全地), four things are necessary. First, we must

understand the language when we hear it spoken. Secondly, we must be able to speak it ourselves, with

confidence(自信) and without hesitation (犹豫). Thirdly, we must do much reading. Finally, we must be

able to write it. We must be able to make sentences that are correct in grammar.

    There are no shortcuts to success in language learning. A good memory is a great help, but it is not

enough only to memorize the rules from a grammar book. It is not much learning by heart long lists(一

览表) of words and their  meanings, studying the dictionary and so on. We must learn by using the

language.

     If we are pleased with a few rules we have memorized, we are not really learning the language. We

must "learn through use." Practice is important. We must practise speaking and writing the language

whenever we can.

1. The most important things to learn a foreign language are _____. 

A. understanding and speaking  

B. listening, speaking, reading and writing

C. writing and understanding      

D. memorizing and listening

2. Someone hears and writes English very well, but he speaks it very badly. This is because _____.  

A. he doesn't understand the language when he hears it spoken

B. he doesn't have a good memory

C. he always remembers lists of words and their meanings

D. he often hesitates(犹豫) to practise speaking it

3. One can never learn a foreign language well by _____. 

A. doing much practice       

B. studying the dictionary

C. learning through use        

D. using the language

4. Which is the most important in learning a foreign language?  

A. A good memory.  

B. Speaking.      

C. Practice.    

D. Writing.

5. "Learn through use" means _____. 

A. we use a language in order to learn it  

B. we learn a foreign language in order to use it

C. we can learn a language well while we are keeping using it      

D. B and C.

卵巢绒毛膜上皮癌

A．雌激素升高
B．AFP升高
C．CAl25明显升高
D．HCG升高
E．17酮17羟类固醇升高

1:2000数字线划图地物点对邻近野外控制点的平面位置中误差，当地形类型为平地、丘陵地时，不得大于______m。

A．0.3
B．0.6
C．0.8
D．1.2

接了漏电开关之后,设备外壳就不需要再接地或接零了。