割煤及移架后要做（）防止片帮.漏顶。
A.伸缩梁及时支护住顶
B.护帮板及时支护住帮
C.立柱及时升劲
D.及时推溜
参考答案：A, B, C
Experts think that _______ recently discovered painting may be _____Picasso.
A．the;/
B．a; the
C．a; /
D．the; a
A．
B．
C．
D．
