按羟基所连接的碳原子不同，醇可以分为（）三类。
A.伯醇
B.仲醇
C.叔醇
D.季醇
参考答案：A, B, C
A. how she was pleasedB. how excited she was C. how happy was she D. she was how happy
《土壤环境质量标准》(GB 15618—1995)中标准分为( )级。
A．一
B．二
C．三
D．五
