sth.is sth.,and is sth.和 sth.is sth.,and it is sth.哪个正确?(sth
Sth is done sth by sb
such is sth that...
it is possible to do sth和it possible to do sth谁是正确的
It is possible for sb(sth) to do sth
it is my frist time to do sth / or doing sth/or do sth?
It is time to do sth和It is time for sth有区别吗?
is he do/dong sth?
sb.is up to sth.
she is sth.with sb.
可以说It is easy doing sth吗
it is difficult doing.sth造句
it is n.to do sth.