题目

When I was 17, I read a quote(引语)that went something like: “If you live each day as if it were your last, someday you’ll most certainly be right.” It made an impression on me, and since then, for the past 33 years, I have looked in the mirror every morning and asked myself, If today were the last day of my life, would I want to do what I am about to do today?     Remembering that I'll be dead soon is the most important tool I've ever encountered to help me make the big choice in life.    About a year ago I was diagnosed with cancer. The doctors told me this was almost 如图16-1-15所示开始时矩形线框与匀强磁场的方向垂直，且一半在磁场内，一半在磁场外.要使线框中产生感应电流，下列方法中可行的是（　　） 图16-1-15A.将线框向左拉出磁场B.以ab边为轴转动（小于90°）C.以cd边为轴转动（小于60°）D.以bc边为轴转动（小于60°）