A:4种
B:6种
C:16种
D:32种
草原上,一只老鼠发觉老鹰在上空盘旋,便紧张而迅速地钻进附近的巢穴内.老鼠的这种行为体现了生物( )
中国近代历史上空前的一次思想大解放运动是( )
—I am really struck by your spoken English. You speak so fluently. Have you been abroad?
—Yes. I ______ in London for two years.