Question

Allen has decided that he will be an engineer by the time he ________ twenty.

A．had beenB．is going to be

C．will beD．is

 

Answer 1

D

【解析】答案：D　考查考生对题干和动词时态的理解及掌握情况。句中by the time相当于when，用来引出时间状语从句，从句中需用一般现在时表将来，故选D。