题目

It is reported that the floods have left about _________ people homeless. A. two thousand        B. two-thousands            C. two thousands         D. two thousands of 答案：A静电场中任何两条电场线______（选填：能，不能）相交，电场线______的地方电场强度大．______（选 填：正，负）电荷在电场中受到的电场力方向就是该店的电场方向，也就是电场线上该点的______方向．