It isn't likely that I should accept such an offer as that.

　　我不可能接受像那样的帮助。

　　2．It＋be＋名词(短语)(a pity, a shame, good news, a fact, an honour, a wonder, no wonder等)＋that从句

　　It's no wonder that he didn't want to go.难怪他不想去。

　　3．It＋be＋过去分词(said, told, heard, reported, decided, suggested, advised, ordered, remembered, thought, considered, well­known, announced等)＋that从句

　　It is decided that the meeting has been put off until next Monday.会议被推迟到下周一已经定下来了。

　　[特别注意]　在"It＋be＋suggested/advised/ordered/requested/insisted/required ...＋that从句"结构中，从句谓语应用"(should＋)动词原形"。

　　It is suggested that you (should) spend more time in studying English.建议你花更多的时间学习英语。

　　4．It＋特殊动词或短语(seem, appear, happen, matter, turn out, occur to, make no difference等)＋that从句

　　It suddenly occurred to her that Joe was afraid of being alone.

　　她突然想到乔害怕独自一个人待着。

　　(三)whether与if的用法

　　1．用whether或if均可的情况

　　(1)whether可引导各种名词性从句。引导大部分动词后的宾语从句时，两者均可。

　　(2)it作形式主语，且主语从句在句末时，两者均可引导主语从句。

　　It's uncertain whether/if he'll come this evening.

　　他今天晚上是否会来还不确定。

　　2．用whether而不用if的情况

　　(1)主语从句和宾语从句置于句首时；

　　Whether we can have clean drinking water lies in what effective measures will be taken by the government about water pollution.我们能否有干净的饮用水取决于政府将采取什么样的有效措施处理水污染问题。

　　(2)引导表语从句和同位语从句时；

The problem is whether the air pollution can be controlled.问题是空气污染能否被控制住。