机械密封的动压实验一般应连续运转（）小时。
A、8
B、6
C、4
D、2
参考答案：C
Our English teacher _____ by the teachers and students.
A．is good thought of
B．is thought high of
C．is sung highly praise for
D．is spoken highly of
丝及绢丝制针织或钩编男睡衣裤
