他正在处理法律文件。

He is dealing with ___legal documents.

在这个州，21岁以下的人买酒是不合法的。

It's not ___legal to buy alcohol under 21 in this state.

这份合同是合法的，双方都签字了。

This contract is ___legal because both parties have signed it.

他在一家大型律师事务所处理法律事务。

He deals with ___legal matters at a large law firm.