控制型转向架装用在C63、C63A型车时,应装用()。
A.提速轮对
B.减重轮对
C.提速且减重轮对
D.RD2型轮对
参考答案:D
—By the way,have you moved into the new house?
—Not yet.The walls ________.
A.were painted
B.are being painted
C.are painted
D.are painting
某有机物含有下列一种官能团,该有机物既能发生消去反应、氧化反应和酯化反应,又能跟某些活泼金属发生置换反应,该官能团最可能的是
A.—Cl
B.—OH
C.—COOH
D.—CHO