安放测量排气温度的温度计，其套管插入排气管内的深度不小于管径的（）。
A、1
B、1/3
C、2/3
参考答案：B
— Why didn't you attend the party ________ in the hall the other day?
— I just wanted some quiet time by myself.[ ]
A. held
B. being held
C. to be held
D. holding
（）都随时间作有规律变化的电压或电流，叫做交流电。
