柜员发生现金差错时以下做法是错误的（）.
A、私自外出查找
B、私自填补
C、立即向营业部主任及网点负责人报告
D、以长补短
参考答案：A, B, D
Qian Xuesen tried many times _________ he found the solution to the puzzle about space technology.
A．after
B．before
C．since
D．when
社会抑制
