题干
Tom often me my English.
A：help; with
B：helps; with
C：help; does
D：helps; does
答案(点此获取答案解析）
B
Tom often me my English.
A：help; with
B：helps; with
C：help; does
D：helps; does
，现在用力将活塞推．使容积减小到
，则汽缸内的压强为 。(填选项前的编号)
