According to the American law, parents must keep their kids _______ except when they are in school.

A new case study says Chinese companies face tough _____in the US and have a long way to go to be successful.

I have no idea of what is in fashion nowadays, so my choice might be quite     ____  .

_____ people food, housing and jobs is what a government should first consider after a natural disaster happens. 

(2013·新课标Ⅰ，32)There's no way of knowing why one man makes an important discovery________another man，also intelligent，fails.