基因工程中实现目的基因与载体DNA共价拼接的酶是 A．DNA聚合酶 B．RNA聚合酶

阅读理解。

     Many people like animals, and often keep one or more of dogs and cats as pets(宠物). If you keep a dog or a cat

as a pet, you must look after it.

     A grown-up(成年的)dog needs two meals a day-not more. It can eat meat, fish, rice and some other things. Dogs

like bones(骨头), but you can't give them chicken bones. Remember to give them a lot of clean water.

     A dog should have a clean, dry box for sleeping(睡觉) in. Washing it once a week is good for its health. If it is ill,

take it to a vet(兽医). A healthy dog will bring you more pleasure.

     Be careful when you choose(挑选)a cat. A cat has two meals a day with some meat or fish. It drinks a little milk

every day. Sometimes you can give them vegetables to eat. Don't forget that they need clean water to drink.

     Take good care of your pets. They will be your good friends. Maybe they can give you some help when you are

in need.

Answer the questions.

1. What do dogs like eating?

__________________________________________________

2. Will pets be people's friends?

__________________________________________________

3.What kind of bones can't we give to the dogs?

__________________________________________________

4. What do cats like eating?

__________________________________________________

5. Why do we give cats and dogs two meals a day?

__________________________________________________

无效票

指挥员一旦作出灭火救援决策后，即使火场情况发生突变，也要坚决将作战意图贯彻到底。（）

在常温下，Fe与水并不起反应，但在高温下，Fe与水蒸气可发生反应。 应用下列装置，在硬质玻璃管中放入还原铁粉和石棉绒的混合物，加热，并通入水蒸气，就可以完成高温下“Fe与水蒸气的反应实验”。 请回答该实验中的问题。

（1）写出该反应的化学方程式__________________，其中氧化剂是________，还原剂是_________。

8．4g铁粉参加反应，转移电子_________mol。

（2）玻璃管中石棉绒的作用是_______________，实验开始时应先点燃___________，实验结束时应先熄灭______________。

（3）圆底烧瓶中盛装的水，该装置受热后的主要作用是__________________________；烧瓶底部应事先放置_________________，其作用是________________________。

下列关于数据操纵模块功能的叙述中，哪一个是不正确的？

A．支持对数据的修改

B．支持数据的检索

C．支持在数据库中创建视图

D．支持嵌入式查询