我国的天然气主要分布于______。
A．塔里木盆地
B．云贵高原
C．渤海湾
D．四川盆地
参考答案：A,C,D
Mr. Smith was thinking about how to explain to the manager why he was late for work, when a good idea ______ to him.
A．happened
B．brought
C．occurred
D．struck
设a/b=2/3那么(a+3b)/(3a+b)的值是( )。
A．10/9
B．11/9
C．7/9
D．5/7
