23. Nowadays, children always complain that their parents are out of date, ______ parents can’t approve of what their children say and do.

A．while

B．thus

C．therefore

D．Otherwise

健全党和政府主导的维护群众权益机制，统筹协调各方面利益关系，有效预防和化解各类社会矛盾要完善（）。

A.司法制度

B.律师制度

C.信访制度