两个句子加一个短语的的翻译

1.take advantage of利用。。。。。。。
2.It is 2 weeks since he joined the party.他入党两周了
3.It is 2 weeks since he was in the party.从他参加聚会到现在，已经两个星期了。

1.有机可乘
2.这是2个星期，因为他入党。
3.这是2个星期，因为他在党。