一空间有垂直纸面向里的匀强磁场B，两条电阻不计的平行光滑导轨竖直放置在磁场内，如图所示，磁感应强度B=0.5T，导体棒ab、cd长度均为0.2m，电阻均为0.1Ω，重力均为0.1N，现用力向上拉动导体棒ab，使之匀速上升（导体棒ab、cd与导轨接触良好），此时cd静止不动，则ab上升时，下列说法正确的是（   ）

— No. It       be her. She left for Shanghai yesterday.

分别通读下面两篇短文，根据短文内容，从A、B、C 三个选项中选出可以填入空白处的最佳答案。

    When I was in high school, I didn't do well in my schoolwork at first.1 I wanted to go to college. I went to talk with my favorite teacher. He told 2 that there might be no chance for me to go to college. It made me very 3 .

    But I didn't give up (放弃). I might not be able to get into 4 . But I wouldn't stop 5 . Then I found that my 6 in the past was spending too much time on science. I was not good at my schoolwork, because I wasn't working hard on all 7 .

    So during the following semesters I 8 my plan. I spent more time in studying English, math and other subjects. I worked hard by 9 to the teachers carefully in class and doing more exercises after class. Now I am studying at college.

    If you are not doing well at school at the moment, don't 10 . Forget the past years and restart (重新开始) now! I believe all your dreams can come true.