在振动中，振体在1s内振动的次数叫（）
A．频率
B．单位频率
C．圆频率
D．弧度频率
参考答案：A
When they met ten years later, they talked happily about the people and the things ________ they remembered on the school football team.
A．who
B．which
C．what
D．that
我国交通法规定，连续驾驶超过（）小时未进行休息视为疲劳驾驶。
A.2
B.3
C.4
D.1
