用肉眼观察，弱磁选精矿的颜色发黑且亮，粒度较细，含单体脉石及连生体颗粒极少，这种产品含铁品位（）。
A.低
B.高
C.一般
D.无法确定
参考答案：B
---I’m afraid I don’t have the ability to make a speech in public. I’m too nervous.
---Don’t worry. You will overcome it _______if you practice more.
A．by and by
B．side by side
C．hand in hand
D．face to face
