浮选系统入料粗粒较多可造成浮选尾矿灰分过低。
参考答案：对
This machine is very easy . Anybody can learn to use it in a few minutes. [ ]
A. operating
B. to be operating
C. operated
D. to operate
无论是哪一年，下半年的天数总比上半年的天数要多．______．（判断对错）
