题目:
When Nigeria achieved full independence in 1960, they had already established a federal political structure consisting of three regions based on the three major population clusters that were in its borders.
选项:
A、 they had already established a federal political structure consisting of three regions based on the three major population clusters that were in
B、 they already had established a federal political structure consisting of three regions that was based on the three major population clusters inside
C、 they already had established a federal political structure that consisted of three regions based on the three major population clusters in
D、 it had already established a federal political structure that consisted of three regions based on the three major population clusters within
E、 it already had established a federal political structure consisting of three regions being based on the three major population clusters it had within
答案:
D