“世界屋脊”青藏高原位于 [ ]
A．亚洲
B．非洲
C．欧洲
D．南美洲
答案：A
68. When the boy playing by the river fell into the river, I was out of the room _______.
A．in flash
B．in a flash
C．as a flash
D．for a flash
死区
