A．a→b→c→d B．b→c→a→d

C．b→d→a→c D．d→b→a→c

答案　C

重点词汇

1．It has occasionally been done.偶尔做这件事。

(1)occasionally adv.偶尔；有时

(2)occasion n．场合，时机

on this/that occasion 在这个/那个时候

on the occasion of在......之际

(3)occasional adj.偶尔的，间或发生的

(1)I met the famous star on several different occasions.我在几次不同的场合见过那位明星。

(2)He was presented with the watch on the occasion of his retirement.他在退休时获赠这块手表。

(3)We occasionally(occasion) meet for a drink after work.我们下班后偶尔相聚小酌。

(4)An occasional(occasion) nap would help.

偶尔打个盹是有好处的。

2．Do you agree or disagree that advertisements are entertaining？你赞同还是不赞同广告是有趣的？

(1)entertaining adj.有趣的；令人愉快的

(2)entertain vt.& vi.娱乐；招待，款待

entertain sb. (to sth. ) (用......)招待/款待某人

entertain sb. (with sth. )(用......)使某人快乐

(3)entertainment n．文娱节目；招待，款待

to one's entertainment使某人感到有趣的是