Ultrafines
超細粉末
??? 情景例句
Sure. Where are you going?
當然。您要去哪里？
I think you may have something there.
我認為在那方面你可能是有理的。
Oil rigs have to be repaired frequently and divers,who often have to work in darkness a hundred feet under water,
鉆井平臺需要經常修理，潛水員常常要在水面100英尺以下摸黑工作，