过量空气系数是一个（）的数 A.等于1 B.大于1 C.小于1 D.大于0

阅读下面短文，从短文后各题所给的三个选项（A、B和C）中，选出可以填入空白处的最佳选项。

When I was walking down the street the other day, I happened to find a small wallet lying there. I picked it up and opened it to see if I could find out the owner’s   46   . There was nothing inside except a little money and an old   47  —a picture of a woman and a girl about sixteen years old. The young girl    48  the woman. I put the photo back and took the wallet to the

   49   station. I handed the wallet to a policeman.

That evening I went to have    50   with my aunt and uncle. They also    51  a young woman. So there were   52   people at table. Her face was familiar. I was quite    53   that we had met before, but I couldn’t    54   where I had seen her. During the talk, the young woman happened to mention that she had lost her wallet that afternoon.   55   I knew where I had seen her. She was the mother of the young girl in the photo. She was very surprised, of course, when I was able to tell her about her wallet.

小题1:A. wallet                                                     B. name                                       C. money

小题2: A. book                                                      B. table                                        C. photo

小题3: A. looked like                                           B. took care of                           C. worried about

小题4:A. bus                                                        B. railway                                    C. police

小题5:A. dinner                                                    B. breakfast                                C. lunch

小题6:A. found                                                      B. invited                                     C. had

小题7:A. three                                                       B. four                                          C. five

小题8:A. true                                                         B. right                                       C. sure

小题9:A. get                                                    B. remember                              C. forget

小题10:A. Suddenly                                       B. Unluckily                                 C. Sadly 

给你一把毫米刻度尺，一根细铜丝和一根铁钉，用什么方法可以较准确地测出铁钉的直径？写出实验步骤和相应的计算公式．

电控汽油喷射系统按对进气量检测方式的不同可分为（）、（）。

痛是由多种因素导致气血凝滞，阻塞不通而成。