电能生产过程中会产生（）等污染物质。
A.氧化硫
B.氧化氮
C.灰渣
D.废水
参考答案：A, B, C, D
--Good morning, sir! _________?
-- I'd like to buy a sweater for my daughter.
A．What can I do for you
B．What are you doing
C．How about the sweater
D．Can you help me
创业投资基金的主要投资对象是股票、债券、证券投资基金等。
