贮存石棉、纤维制品时()
①尽可能处于松弛状态
②尽可能竖放或悬挂
③避免与工具、配件等硬物混放
④防潮、防油
A.①②③
B.②③④
C.①③④
D.①②④
参考答案:C
Could you lend me 50 pence? ______, I’ll have to change a £10 note into coins.
A.Therefore
B.Instead
C.Otherwise
D.Yet
“歼-10”是我国自行研发的新型战机,当发动机以1.2×105N的推力使其以二倍声速(声速为340m/s)飞行时,10s内发动机对飞机做功为______J,发动机推力的功率是_________W.