每周二次的外文缩写是
A．bid
B．biw
C．qd
D．qid
E．tid
参考答案：B
—_______ does your mother go to the supermarket?
—She takes a bus. [ ]
A.How
B.How often
C.How long
D.How much
下列矿物具有良好的天然可浮性是石蜡
