207. In the textbook publishing business, the second quarter is historically weak, because revenues are low and marketing expenses are high as companies prepare for the coming school year.
a low and marketing expenses are high as companies prepare
b low and their marketing expenses are high as they prepare
c low with higher marketing expenses in preparation
d low, while marketing expenses are higher to prepare
e low, while their marketing expenses are higher in preparation
请问答案Ａ中的ＡＳ 是什么意思，怎么试图翻译，可就是说不同呀～！
另一个问题是：不是两个独立的句子要是用ＡＮＤ 连接的话不是之前要加逗号的吗？否则不就是ＲＵＮ－ＯＮ ＳＥＮＴＥＮＣＥ吗？那么本句怎么就对了？ | 
