He is a merry man _________ red clothes.[ ]
A. on
B. at
C. in
答案：C
—This box is too heavy.
—Well, we have got some ________ ones. They’re over there, on the desk.
A．expensive
B．light
C．easy
D．small
对于无缝线路长钢轨工地焊接，质量最易受控的方法是（）。
A.气压焊
B.闪光接触焊
C.铝热焊
D.电渣压力焊
