抽油机刹车行程过大时应重新调整刹车（）。A、复位弹簧 B、轮轴 C、轮毂 D、连杆

首字母填空 （本大题共5分，每空0.5分）

根据对话内容和所给首字母，在空格内填入一个适当的单词，使对话意思完整。 

Dear Lily,

I’m happy to get your letter. I r 小题1: it after school today. Now let me tell you a小题2:    me. I like swimming. I swim every day in s小题3: . You know summer in England is very hot. I also like reading. I read different k小题4: of books. I read two o小题5:  three books a week. I like w小题6: , too. I want to be a writer(作家) in the future(将来)

I also like playing w小题7: my dog, Mickey. He is big and needs a lot of exercise. So at weekends we often go for a long w小题8: near my house. Mickey likes jumping into water. He is a good swimmer.

Well, these are my h小题9: . Please write and tell me about y小题10:  .

All the best

Amy

乙烯和乙烷的混合气体共a mol，与b mol O₂共存于一密闭容器中，点燃后充分反应，乙烯和乙烷全部消耗完，得到CO和CO₂的混合气体和45 g H₂O，试求：

（1）当a＝1时，乙烯和乙烷的物质的量之比n（C₂H₄）∶n（C₂H₆）＝         。

（2）当a＝1，且反应后CO和CO₂的混合气体的物质的量为反应前O₂的时，b＝       ，得到的CO和CO₂的物质的量之比n（CO）∶n（CO₂）＝       。

（3）a的取值范围是           。

癌症是指()

A．所有恶性肿瘤的统称

B．所有肿瘤的统称

C．癌和肉瘤

D．间叶组织发生的恶性肿瘤的统称

E．上皮组织发生的恶性肿瘤的统称

电路中所接的负载起（）作用。

A、传递电能

B、供给电能

C、取用电能

既属于输穴又属于八脉交会穴的是()

A.足临泣

B.足窍阴

C.照海

D.申脉

E.外关