Why dinosaurs died out remains a puzzle.恐龙为什么会灭绝仍然是个谜。

　　Where the English evening party will be held has not yet been decided.

　　英语晚会将要在哪里举行还没有决定。

　　When we will have a meeting is an important question.我们何时举行会议是个很重要的问题。

连接词有:　　　　　　　　;在句中　　　　　　　　(作/不作)句子成分。连接代词有　　　　　　　　;在句中作　　　　　　　　。

连接副词有:　　　　　　　　;在句中作　　　　　　　　。

　　Step.Ⅲ.主语从句与形式主语it

　　1.It+be+形容词+主语从句,如:

　　It is uncertain whether he can come to Jenny's birthday party or not.

　　他是否能够参加詹妮的生日聚会还不确定。

　　2.It+be+名词(词组)+主语从句,这类名词有:

　　a fact,a pity,a shame,an honour,a question等,如:

　　It's a pity that you missed the exciting football match.很可惜你错过了激动人心的足球比赛。

　　It remains a question whether he will come or not.他是否会来还是个问题。

　　3.It+be+过去分词+主语从句,这类过去分词有:

　　announced,believed,expected,hoped,decided,reported,said,shown等,如:

　　It is reported that 16 people were killed in the earthquake.据报道,16人在地震中丧生。

　　It is not decided who will give the operation to the patient.谁给病人做手术还不确定。

　　4.It+不及物动词+主语从句,这类不及物动词有:appear,happen,seem等,如:

　　It seemed that he didn't tell the truth.似乎他没有说实话。

　　It happened that I was out when he called.碰巧他打电话时我出去了。

　　Step Ⅳ.主语从句的注意事项

　　1.从句的语序用陈述语序

What you need is more practice.你需要的是更多的练习。