■ call for

1) 提出要求或呼吁（call for 在这里是个瞬时行动，属第四类动词），除非是某一主张的内容，否则不用一般现在时。

• The declaration called for an immediate cease-fire.声明呼吁立即停火。
• They passed a resolution attacking the government and calling for financial aid for the miners.他们通过了一份决议，抨击政府，并要求给与矿工们以经济补助。
• But it (=emergency treatment) was never called for, and when help arrived it was too late.但是一直没有提出要紧急抢救，到人们前来抢救，为时已晚。

2) 需要（call for 在这里是个延续状态，属第一类动词），可以用一般现在时。

• Controlling a class calls for all your skill as a teacher.管好一个班级，需要你使出教师的浑身解数。
• Apology is called for.需要表示道歉。
• Bold action was called for.当时需要采取果敢的行动。