A:
B:
C:
D:
Attention, please! All the mobile phones ____ ____ ____ ____ before the meeting starts.
经过任意三点中的两点共可以画出的直线条数是____条.
It's certainly hard work. But, a man who wishes to have a career has to make a great many sacrifices.
①地形因素 ②纬度位置 ③海陆位置 ④冬季风的影响