下列选项中，哪种动物是2014年冬季奥林匹克运动会的吉祥物（）。
A.白鳍豚
B.非洲象
C.雪豹
参考答案：C
I have many friends. I don't know whom ______ first. [ ]
A. talk with
B. to talk
C. to talk with
D. talk
什么是超标准耗能？
