膀胱癌最常见的起始症状是（）
A．尿频尿痛
B．排尿困难
C．血尿
D．腹部肿块
E．尿路梗阻
参考答案：C
解析：
血尿是最常见的起始症状。
John: _________
Jack: In two weeks.
John: Are you going to Japan?
Jack: No. I'm going to Australia. I went to Japan two years ago.
A．How long have you been here?
B．When is your holiday?
C．When are you leaving for Australia?
D．How long do you plan to stay here?
铝及铝合金工件和焊丝表面清理后，在潮湿的情况下，一般应在清理（）小时内施焊。
