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_____ succeed in doing anything.
\_\_\_\__ succeed in doing anything.
Hardly I had sat down when I heard someone knock at the door.
Hardly I had sat down when I heard someone knock at the door.
The Philippines _____ to the south-east of China.
The Philippines \_\_\_\__ to the south-east of China.
I received his mother’s telephone call at eleven. _____ that he was badly hurt in an accident yesterday.
I received his mother’s telephone call at eleven. \_\_\_\__ that he was badly hurt in an accident yesterday.
Mary found _____ extremely difficult to pass the examination.
Mary found \_\_\_\__ extremely difficult to pass the examination.
_____ got in the wheat than it began to rain heavily.
\_\_\_\__ got in the wheat than it began to rain heavily.
No sooner _____ arrived at the station than it began to snow.
No sooner \_\_\_\__ arrived at the station than it began to snow.
设有一匀强磁场局限在图示的虚线范围内，磁感应强度为B，有一边长为L的正方形线圈abcd，其两边如图示那样，位于磁场中，线圈平面与磁场方向垂直，线圈中的电流为I，方向如图所示，则线圈受到的力的大小为____，方向为____．
设有一匀强磁场局限在图示的虚线范围内，磁感应强度为B，有一边长为L的正方形线圈abcd，其两边如图示那样，位于磁场中，线圈平面与磁场方向垂直，线圈中的电流为I，方向如图所示，则线圈受到的力的大小为\_\_\_\_，方向为\_\_\_\_．