新问og89

89.   A recent national study of the public schools shows that there are now one microcomputer for every thirty-two pupils, four times as many than there were four years ago.

(A) there are now one microcomputer for every thirty-two pupils, four times as many than there were

(B) there is now one microcomputer for every thirty-two pupils, four times as many than there were

(C) there is now one microcomputer for every thirty-two pupils, four times as many as there were

(D) every thirty-two pupils now have one microcomputer, four times as many than there were（C）

(E) every thirty-two pupils now has one microcomputer, four times as many as

我想问，Ｄ中there were可以省略不？象Ｅ那样。ＯＧ分析Ｅ的错误时没说there were的问题。什么时候该省略什么时候不省略？把握不住．