距今170万年到公元前21世纪，是我国的原始社会时期。( )
参考答案：对
图上距离一定比实际距离小。[ ]
I like these photos and they can _____ me _____ the life living in the country. [ ]
A. think…of
B. remind…of
C. let…down
D. wake …up
