溃疡性结肠炎的主要临床表现为（）
A.腹痛
B.黏液脓血便
C.腹胀
D.恶心、呕吐
E.发热
参考答案：B
— Michael, what's your favorite subject?
— _____. It's interesting. We can enjoy songs in class. [ ]
A. Math
B. Physics
C. Music
制动缸活塞皮碗弹力不足时更换。
