医生给心脏疾病的患者做手术时，往往要用一种称为“人工心脏泵”（血泵）的体外装置来代替心脏，以推动血液循环．如图是该装置的示意图，线圈AB固定在用软铁制成的活塞柄上（相当于一个电磁铁），通电时线圈与活塞柄组成的系统与固定在左侧的磁体相互作用，从而带动活塞运动．活塞筒通过阀门与血管相通，阀门S₁只能向外开启，S₂只能向内开启．线圈中的电流从B流向A时，螺线管的左边是____极，血液从____流入____．（后2空选填①、②、③）．

第三届世界互联网大会，是由中国倡导并举办的互联网盛会，于2016年11月16日至18日在                举办。大会的主题是“创新驱动造福人类──携手共建网络空间命运共同体”。（   ）

四位同学参加知识竞赛，每位同学须从甲乙两道题目中任选一道题目作答，答对甲可得60分，答错甲得﹣60分，答对乙得180分，答错乙得﹣180分，结果是这四位同学的总得分为0分，那么不同的得分情况共计有____种．

一位美国记者赞叹道：“每一场革命都有它自身的传奇，***率领数万工农红军所完成的战略转移，就是中国革命史上的伟大传奇．”“伟大传奇”是指（　　）       

根据短文内容，选择合适的句子填入文中空格处，使短文意思完整。

Dear Li Lei,

    How are things going? 

    Last week I went to Kunming with my family. ____ The weather was nice and warm. We stayed in a nice hotel（宾馆）with a large yard. ____ We went swimming a lot. That was interesting. We had meals in the hotel, too. ____ We also ate a lot of fruits like bananas, pears and pineapples (菠萝).

    On Friday, we went to Shilin by bus. The mountains were very beautiful and I took lots of photos. ____ The clothes in the shops were very nice! I liked them very much. ____ Mother told me not to buy any. And I was not happy. But I enjoyed the trip to Kunming.

    What about your trip?

    I hope all is well with you.

Yours,
Han Meimei

A. There was a swimming pool in the hotel.

B. I wanted to buy some.

C. The next day we went shopping.

D. I had a wonderful time there.

E. The food was delicious.