请问嵌套查询的linq语句怎么写

请教嵌套查询的linq语句如何写？
select aid, (select bid from b where bid = a.aid) from a
请问这条语句如何改成linq的写法？

[解决办法]
from item in table1
select new
{
AID=aid,
BID=from item1 in b where bid = item.aid selct bid
}
[解决办法]
from item in a
where (from t in b select bid).Contains(aid);