电镜样品包埋常用的环氧树脂要求的聚合环境是（）。 A.4℃，24小时 B.60℃，2

阅读短文，回答问题。

     One day, long ago, a little baby was born. His name was Jesus. Jesus was a special baby.

Many people say he was the son of God. When he was born, a new star shone in the sky.

Three wise men saw the star. They followed the star to Jesus. They brought the baby special

gifts. They knew he was a special baby. When the baby grew into a man, he was a great teacher.

Jesus's birthday is Christmas day. We give gifts to our friends and family at Christmas. We put

stars on our Christmas trees, too.

1.Who was born long ago?

______________________________________________

2.Did three wise men see the star?

______________________________________________

3.What did they bring to the baby?

_______________________________________________

4.When is Jesus's birthday?

_______________________________________________

5.Do you put stars on your Christmas trees?

_______________________________________________

连词组句。

1. have, I, a, bedroom

                                                   .

2. shoes, his, are, his, bed, below 

                                                   .

3. in, the, evening, bed, goes, to, he

    ___________________________.

4. His, lamp, his, bed, beside. Is

    ___________________________.

5. bedroom, he, likes, his

    ___________________________.

设N_A为阿伏加德罗常数的数值，下列说法正确的是（  ）

A．在1 L 0.2 mol·L^－1的Na₂CO₃溶液中含有CO₃^2—的数目为0.2N_A

B．0.1 mol Fe参加氧化还原反应，转移的电子数目一定是0.3 N_A

C．15.6 g Na₂O₂与过量CO₂反应时，转移的电子数为0.2N_A

D．1 mol Na₂O₂中含有的阴离子数目为2N_A

协议收购时，收购人拥有权益的股份达到该公司已发行股份的（），继续进行收购应当依法向该上市公司股东发出要约。

A.20%

B.30%

C.40%

D.50%+

简述轴流式压气机转子的组成。