用碳作还原剂,还原过程全部是()反应。
参考答案:吸热
设c∈R,函数f(x)=x2-2x+c.关于函数f(x)的下述四个命题中,真命题为( )
A.f(0)>f(2)
B.f(0)<f(2)
C.f(x)≥c-1
D.f(x)≤c-1
" Nice to meet you. " " _____ " [ ]
A. Thank you.
B. Nice to meet you,too.
C. Don't say so.
D. I'm fine.