送行服务主要包括的服务内容有：( )。A．致欢送词 B．提前到达机场(车站)，照顾

阅读理解。根据信的内容，回答下列问题。

Dear John,

     Thank you very much for your letter. I am glad that you enjoyed your holiday with me. We enjoyed having

you and your sister here. We hope that you will both be able to come again next year. Perhaps you'll be able

to stay longer next time. A week is not really long enough, is it? If your school has five weeks' holiday next

year, perhaps you will be able to stay with us for two or three weeks.

     We have been back at school three weeks now. It feels like three months! I expect that you are both

working very hard now because you are in Grade Two now. Tom and Ann won't be in Grade Two until

2007. They went for a picnic yesterday but I didn't go with them, because I hurt my foot and I couldn't walk

very well. They went to an island and enjoyed themselves there.

     Tom, Ann and I send our best wishes to you. We hope to see you soon.

                                                                                                                                                  Yours,

                                                                                                                                                  Michael 

1. Who stayed with Michael for a holiday?

____________________________________________________.

2. How long did their holiday last for?

____________________________________________________.

3. From the sentence "It feels like three months!",

    we know that Michael has no interest in learning, right?

____________________________________________________.

4. Who will be in Grade Two in 2007?

____________________________________________________.

5. Why didn't Michael go to the island for a picnic yesterday?

___________________________________________________.

1947年6月，_________、_____________率军千里跃进大别山。

天枢是（）

A、手阳明经穴 

B、手少阳经穴 

C、足阳明经穴 

D、足太阳经穴 

E、以上都不是

胰岛B细胞分泌（）

A.胰岛素

B.高血糖素

C.生长抑素

D.胰多肽

E.促胰液素

简述病毒的复制周期。