在文档中插入表格后，单元格的高度和宽度（）.
A.固定不变
B.可以改变
C.高度可以改变，宽度可以改变
D.宽度可以改变，高度不可以改变
参考答案：B
_____ to find a job after graduation from college, he had to depend on his parents for a living. [ ]
A. Being not able
B. Not being able
C. To be not
D. Not to be
电磁波的绕射使信号质量产生影响，其影响程度（）。
A、与建筑物高度无关
B、与频率无关
C、与建筑物高度和频率都有关
