是serious
adj. 严肃的，严重的认真的庄重的危急的
The plague this time is very serious.
这次的瘟疫十分严重。
The consequences could be serious.
后果可能是严重的。
I regard this as a serious matter.
我认为这是一件重要的事情。
The strike caused serious disruptions.
罢工造成了严重的混乱。
Smoking is a serious danger to health.
吸烟严重危害健康。
