大型养路机械发动机每工作()应按操作要求清洗冷却风扇液力耦合器的机油滤清罩。
A、50h
B、100h
C、200h
D、300h
参考答案:C
Could you please _____ me to play computer games tonight? [ ]
A. allow
B. to allow
C. will allow
D. allowing
晶状体的屈光力约为( )
A.43DB.42DC.41DD.19DE.18D