问题 选择题

如图,均匀绕制的螺线管水平放置,在其正中心的上方附近用绝缘绳水平吊起通电直导线A,A与螺线管垂直,A导线中的电流方向垂直纸面向里,开关S闭合,A受到通电螺线管磁场的作用力的方向是(    )

A.水平向左

B.水平向右

C.竖直向下

D.竖直向上

答案

答案:D

题目分析:根据安培定则判断通电螺线管在A处产生的磁场方向:水平向左.

根据左手定则判断可知:A受到通电螺线管磁场的作用力的方向:竖直向上.

D正确。

完形填空

Kate Spotz is a 22-year-old girl from America. She wants to cross the Atlantic Ocean by boat. If she__ ___ , she’ll be the youngest and the first American to finish the 2500-mile trip.

Spotz began___ ____ when she was at university. She has swum all the way down the 325-mile Allegheny River and traveled by bike from Seattle to Washington.

Spotz knows that she______ see some unexpected(想不到的) things during the trip. It will be very______ if she meets very bad weather in the middle of the sea. _____ she believes that she can deal with all the difficulties.  “I had never thought I could run 26 miles,” she said. “But once I ______ it, I realized that maybe I could do something even______.”

Spotz wants to collect______ for an organization called“ Blue Planet Run” by going on this trip. The organization offers free and safe drinking water to people who need it.

It’ll take her about three months to finish this______. Good luck to this______ girl and best wishes to her!

小题1:A. dreams .            B. misses                   C. succeeds

小题2:A. sailing                B. biking                   C. swimming

小题3:A. must                B. may                    C. should

小题4:A. dangerous             B. boring                   C. exciting

小题5:A. If                   B. But                     C. So

小题6:A. saw                  B. met                     C. finished

小题7:A. easier                 B. more difficult             C. more dangerous

小题8:A.food                  B. money                   C. clothes

小题9:A.plan                  B. lesson                   C. trip

小题10:A. brave               B. modern                  C. polite

多项选择题