喷雾水枪包括低压喷雾水枪和（）喷雾水枪。
A.中压
B.中高压
C.高压
D.中低压
参考答案：C
―Everybody wants to know _____.
―He is fine.
A. what does he feel
B. what he feels
C. how does he feel
D. how he feels
氨基化是在分子中引入（）的反应。
A.硝基
B.氨基
C.烷基
