奥运会排球比赛分为排球、()两个项目,每场比赛共分为()局。
A、手球,4
B、沙滩排球,3
C、沙滩排球,5
D、手球,6
参考答案:C
34.I have had some bad times before, but seldom________so helpless as now.
A.I had felt
B.have I felt
C.I have felt
D.had I felt
环境标准体系按类别分为环境质量标准、()、环境基础标准、()、环境标准物质标准、环保仪器标准强制性标准和推荐性标准七类。按照标准制定颁布机关的行政级别分为国家、地方两级。