家具又硬又不舒服，太不结实而且太小巧。The furniture was stiff, uncomfortable, too delicate, and too neat.这书橱很不结实,装不了这么多书.This bookcase is too unstable to hold so many books.鸟的主人说这只鸟可能是从鸟舍一处不结实的地方逃走的。The owner said the bird may have escaped...
The drug can reduce the frequency and severity of attacks.这种药能降低发病次数和严重程度.Accidents are happening with increasing frequency.事故发生得越来越频繁.Speech is made up of sound waves that vary in frequency and intensity.语音是由不同频率和强度的声波组...