PP test1 No.64 语法题 求教

boydd

PP test1:

64. Lactose, a sugar present in milk, is
   one of simple sugars used in food
   preparations for infants.

另有真题，我不知道是哪年的，在高分语法中出现的：

The age of geological sample can be estimated from radio of radioactive to nonradioactive carbon present in the object is examined.

这里，D错的比较明显。则C: present是对的，也就是说其为形容词短语结构作定语。这应该与64题一样，64的B应该没错的。

PP 中64原答案为C，不知道应该怎么改？

robbin23

C
one of the simple sugars.

boydd

多谢robbin,good luck!