老师也难免会犯一些错误,用最恰当的方式指出老师的错误既能够实现教学相长,也是促进师生感情的一种手段。下列属于“最恰当的方式”是()
A:只有在老师主动找自己谈话时才说
B:在课堂上直截了当地指出
C:课后与老师讨论问题时,主动委婉地指出
D:自己不说,让别的同学转达
阅读理解 Tom and his father, Mr. Smith, always go out for a walk after supper every day. After that, he does his homework and watches TV for half an hour. Then he goes to bed. Now Tom and his father are taking a walk along the road. It begins to rain. Tom wants to run for home. But his father says very slowly, “Don't run. Isn't it raining in front of you?”
①若烃与氢气完全反应的物质的量比为1:3,说明该烃的分子结构存在____结构,它是____(写结构简式).
②若烃与氢气完全反应的物质的量比为1:2,说明该烃的分子结构存在____结构,它是____(写结构简式).
③苯乙烯与氢气完全加成的物质的量比为____.
④丁二烯发生加聚反应得到的高分子化合物的结构简式为____
下列各句中,没有语病的一句是( )