A:∀x>0,总有(x+1)ex≤1
B:∀x≤0,总有(x+1)ex≤1
C:∃x0≤0,总有(x0+1) ex0 ≤1
D:∃x0>0,使得(x0+1) ex0 ≤1
海南的____产业比较著名。
下列地理界线中与我国“秦岭——淮河”一线大致一致的是( )。
—Where did you come across your old classmate Jane?
—It was in the supermarket ________ she worked ________ I came across her.
草食家畜能将非粮饲料资源转化为畜产品。近30年来,我国草食家畜养殖量呈现出平稳增长的态势。下图示意1990~ 2011年我国草食家畜养殖重心变迁图,据此完成以下问题。