初二英语！！麻烦各位~~~在线等~急

一、用join或take part in并用适当形式完成下面句子。
（1）Our little brother didn't___join___us for dinner that evening.
(2)The Swiss didn't____take part in_the two world wars.
(3)We___took part in__the country club last year.
二、选用because或because of完成下面句子。
（1）Mary couldn't go to school__because of____her illness.
(2)I went to bed early____because___I was tired.
(3)I don 't like the book_____because____it is boring.
because是_连____词，后面跟的是一个___(表语）从句___。而because of是短语介词，后跟_____名___词或代词等作宾语。
三、(1)这只鸟的叫声很动听（翻译） This bird sings nicely.
(2)Laura came to China at the age of fifteen.(改为同义句）
Laura came to China___when_ _she ____ __was__fifteen.

一.1,join; 2,take part in; 3, take part in.
二.1,because of; 2,because; 3,because; 连词，句子；名词
三.1,This bird sings beautifully
2,when he was

1，join;take part in；join
join 表示从参加某一团体并作为其中一员,如果后接人,则表示参加某人的活动,如: Let's join the children. 我们去参加孩子们的活动.
take part