Especially when it comes to speaking in English and fortunately or unfortunately.
特别是要用英文来演讲,不知是幸运还是不幸。
I wonder whether he's telling the truth.
我不知道他说的是不是实话。
As a shipbuilder, Cockerell was trying to find a solution to the problem of the wave resistance which wastes a good deal of a surface ship's power and limits its speed.