加热炉吹灰的目的是除去烧油加热炉对流段钉头管上积聚的游离炭。（）
参考答案：对
The children went home from the grammar school, their lessons________ for the day. [ ]
A. finishing
B. finished
C. had finished
D. were finished
下列哪项不属于慢性胆囊炎的临床表现（）.
A.嗳气
B.腹胀
C.胆绞痛
D.右腰背部隐痛
E.畏寒、高热，黄疸
