临考 求助2道PREP语法~ 不胜感激！

Jessielynn

今天模考了，几道语法请教一下~

1. Nothing that Federal Reserve had raised a key short-term interest rate again last month, analysts said that they expected orders for durable goods to decline soon because rising interest rates makes it more expensive to buy them on credit.
(A) rising interest rates makes it more expensive to buy them on credit
(B) rising interest rates make buying on credit more expensive
(C) a rise in interest rates make it more expensive to buy on credit
(D) a rise in interest rates make buying on credit more expensive  (B)
(E) a rise in interest rates makes it more expensive for them to be bought on credit

C为什么不好？

2. According to public health officials, in 1998 Massachusetts became the first state in which more babies were born to women over the age of thirty than under it.
(A) than
(B) than born
(C) than they were
(D) then their had been  (A)
(E) than had been born

这道题当时就在A和B之间徘徊，一度倾向于A，最终还是选了B。。。抱憾。。。。求解~

MDN

是不是为了保持简洁呀。
PERP破解112题里提到，“比较对象的主语和谓语相同时，在不影响句子意思理解的情况下，可以省略相同部分，使句子更加简洁。”

Jessielynn

啊呀。。。对哦。。。怎么这么明显的错都没看出来。。。谢谢啊~
第二题呢？

fannybeibei

make should be makes!  (a rise )