一道英语单选,

问题描述:

一道英语单选,
Some studies show that the earth's climate __ by about 0.6C during the past one hundred years .
A.warmed
B.is warming
C.has warmed
D.is to warm

选C,duringthe past one hundred years 意思是“在过去的一百年间”,因此根据时态排除B、D,但是通常during+时间段应和现在完成时态搭配,故选C