屏幕上影像运动的基本来源有（）.
A.对现实生活中运动的再现
B.灯光的移动
C.观众的走动
D.摄像机的运动
参考答案：A, D
Bob often says that swimming is _____________ than hiking in reducing weight, but he always spends more time on swimming.
A．less useful
B．less interesting
C．more useful
D．more interesting
正在输入的记账凭证，对于( )，可不予提示并执行。
A．借贷金额不平衡B．没有余额C．没有数量D．没有会计科目
