[jiā rù]
（加上） add; mix; put in
[动]
（参加） join;accede to;take part in
join in the stream of people
加入人流
accede to a treaty
加入条约
join the Communist Party
加入共产党
All of us joined lustily in the chorus.
我们全都劲头十足地加入了合唱。
As the guide was showing us round the museum, two or three foreign tourists joined themselves on to our party.
导游领着我们参观博物馆时， 有两三个外国游客也加入了我们的行列。
I'll take part in everything good you do.
我将采取一切你做的好的部分。