Polyharmony
復和聲
??? 情景例句
Please accept these gifts with my thanks.
請接受這些禮物以表達我的謝意。
Don't mention it.
不必謝。
and we control it by means of the mud which we circulate down the drill pipe.
我們讓泥漿順著鉆桿向下循環，用這種方法來控制壓力。