is后面加什么动词

is后面的动词一定要用ing。
例句：
Where is Sophy? Is she safe?
索菲在哪儿？她没受到伤害吧？
He is an asthmatic who is also anaemic、
他是一个哮喘病人，并且还贫血。

Eight hours on a bus is no joke, is it、

坐８个小时的公交车可不是闹着玩儿的、，对吧。

He is in no doubt as to what is needed、

他对需要些什么心中有数。

It is a country where corruption is rife、

这是个腐败成风的国家。