主动脉瓣狭窄可触及
A．肝硬化腹水B．急性胃穿孔致腹膜炎C．胰腺囊肿D．癌症晚期恶病质E．腹白线疝
参考答案：A
According to the rules of our school, you may leave the classroom ____ you have the teacher's permission. [ ]
A. unless
B. on condition that
C. though
D. until
质量评定为优良的单位工程，其桩基工程中II类桩（）。
A、不超过70%
B、不超过20%
C、不超过30%
D、不得出现
