充电前，应查看（），电锁应处于（）档位置。
参考答案：电源总开关应在关断位置；LOCK
膀胱肿瘤最常见的临床症状为（）
A.尿频
B.尿急
C.尿痛
D.排尿困难
E.无痛性肉眼血尿
As he works in a remote area, he visits his parents only ______.
A．occasionally
B．anxiously
C．practically
D．urgently
