题目选项分析

Part of the proposed increase in state education spending is due to higher enrollment, with a number of students in public schools growing steadily since the mid-1980's and, at nearly 47 million, reaching a record high.

Part of the proposed increase in state education spending is due to higher enrollment: the number of students in public schools has grown steadily since the mid-1980's and, at nearly 47 million, has reached a record high.