采油指数
参考答案:
油井生产压差每增大0.1兆帕,所增加的油量。
(2011·天津高考)Passengers are permitted______ only one piece of hand luggage onto the plane.
A.to carry
B.carrying
C.to be carried
D.being carried
中国的“东方红一号”卫星是()年发射成功的。
A.1969
B.1970
C.1971
D.1973