由中国境内注册的公司发行，直接在美国纽约上市的股票叫做( )。A．B股B．H股C．

That boy is in Class Two, _____. [ ]

A. too            

B. either           

C. also          

D. as

We should follow the ________ in a foreign country we are visiting. [ ]

A. habits 

B. customs

C. tradition  

D. practice

When John woke up he was in the hospital, but he didn’t know how that had       .

A．been happened

B．come about

C．been come about

D．been taken place

慢性肝病患者，普查发现甲胎蛋白3次阳性，肝功能正常，肝区触诊无异常，诊断为早期肝癌。下列哪项检查对定位最有帮助

A．选择性肝动脉造影

B．放射性核素扫描

C．超声波断层扫描

D．CT检查

E．以上都不是

扑救油罐火灾时，泡沫液的准备量通常应达到一次进攻灭火用量的（）倍。

A、2

B、4

C、5

D、6