A:青藏高原
B:巴西高原
C:伊朗高原
D:中西伯利亚高原
Mr. Wang is a teacher. He ______ in this school for 20 years.
中国近代史以鸦片战争为开端,主要是因为( )
Yesterday my father ___________ his friends ___________ Tian'anmen Square (天安门广场).