Question

(2013·成都一診)Parents are doing all they ________ to help their children achieve their ambitions.

A．shall	B．can
C．may	D．need

Answer 1

B

選B　考查情態(tài)動(dòng)詞。句意：父母?jìng)冊(cè)谧鏊麄兞λ�能及的事�?lái)幫助他們的孩子實(shí)現(xiàn)他們的夙愿。完整形式為“Parents are doing all they can do to help their children achieve their ambitions.”其中they can do是定語(yǔ)從句，修飾先行詞all; to help  their children achieve their ambitions是目的狀語(yǔ)。由于主句中出現(xiàn)了實(shí)義動(dòng)詞doing，所以省略了從句中的do。故答案為B。