Question

Tony, my best friend, has done _______ he can to help me out of trouble.

A．all that

B．all what

C．which

D．all which

Answer 1

A

考查句型：do all (that) sb can to do sth/ do what sb can to do sth尽某人所能去做某事，所以应选A，若选B应去掉all，句意：托尼，我最好的朋友尽他所能帮助我摆脱困境。