China has built green Wall _____the northern part _____the country.

问题描述:

China has built green Wall _____the northern part _____the country.
A:to;to
B:across;of
C:across;on
D:at;of
请解释明白点,我是英语白痴,把我说服了,算话的!

B
话说 你说的是 Great Wall