自动喷水灭火系统应备有备用喷头,其数量不少于总数的10%,且()。
A、数量不少于10只
B、每种型号数量不少于10只
C、按工程实际情报况备
D、最少备20只
参考答案:B
具有清心安神功效的药物是:( )
A.玉竹
B.龙眼肉
C.人参
D.莲子
E.百合
My cousins have collected stamps for two years. They have ______ stamps from different countries.[ ]
A. a few
B. many
C. much
D. little