《招标投标法》规定投标人向招标人和招标代理机构表达争议的方式是（　　）。

A．投诉、仲裁

B．异议、质疑

C．协商、调解

D．调解、投诉

With a lot of difficult problems () , the manager felt worried all the time.

A. settled

B. to be settled

C. settling

D. to settle