og-89

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 micro-computer, four times as many than there were
(E)   every thirty-two pupils now has one microcom-puter, four times as many as

看上去最正确的是C. 但我有个问题：为什么用four times as many as there were? 依我理解，这里作比较的应该是microcomputer的拥有率，那后一个there到底指代什么，应该用单数还是复数? 请各位NN指教~