注水开发的油田中,在通常情况下,渗透率高的油层(),处于砂体主体部位的油层先见水。
A.未见水
B.后见水
C.不见水
D.先见水
参考答案:D
Being able to speak another language fluently is a great ______ when you're looking for a job.
A.chance
B.importance
C.advantage
D.assistant
下列( )选项是合法的标识符。
A.123
B._name
C.class
D.1 first