如图所示,badc是一个“U”型金属导轨,pq是一根金属棒,可以在金属导轨上滑动。金属导轨处于一个蹄形磁铁中,一重物通过定滑轮的细绳与金属棒相连,整个装置置于水平桌面上并处于静止状态。当重物开始下落且pq在磁场内运动的过程中
________ with the courage and determination of the young cancer patient, many people left messages in his microblog, encouraging him to fight with the disease.
Having taken our seats, _______.
The students listened carefully to the teacher with their eyes _____ on the blackboard.
With our knowledge practice , we can make contribution to our society.
The most popular food ______ on menus in western countries is hamburger.