C
在句型 "It is important (necessary,strange,natural) that ." 中,that 后面的从句中的谓语动词用：(should) + 动词原形
It's necessary that we (should) have a walk now.我们有必要出去散散步.
It's natural that she (should) do so.她这样做是很自然的.
It's important that we should take good care of the patient.重要的是我们要照顾好病人.