计数法测量周期时主要存在触发误差、时标误差和量化误差3种。( )
参考答案：对
灰土垫层表面平整度允许偏差为______mm。
A．3
B．5
C．7
D．10
In the past, people celebrated Thanksgiving Day to give thanks to _____.[ ]
A. their family members
B. anyone who had helped them
C. native Americans
D. everyone
