我国能源企业在支撑国民经济增长和社会发展中发挥了巨大作用,能源自给率一直保持在()以上的较高水平。
A.90%
B.85%
C.80%
D.75%
参考答案:B
The book, which _______ children, became popular with adults.[ ]
A. was planned for
B. was meant by
C. was intended for
D. was designed by
逆中介化假说包括以下哪几个层面()
A.电子沟通效应
B.电子中介效应
C.电子营销效应
D.电子整合效应