A:④过程中①的干重不断增加
B:④过程初期需要添加必需矿质元素
C:①到幼苗过程细胞中核DNA的种类不变,RNA不同
D:若③中细胞的基因型为EeFf,则②中细胞的基因型为EeeFff
定义在R上的函数y=f(x)满足f(x+6)=f(x),当-3≤x<-1时,f(x)=-(x+2)2,当-1≤x<3时,f(x)=x则f(1)+f(2)+f(3)+⋯+f(2012)= ( )
A: Excuse me! ____
B: Yes. Please keep your desk clean.
A: ____
C: Wow! Your picture is so beautiful!
B: ____
C: Oh, I'm sorry. ____
B: Sure!
C: ____
B: Yes, work quietly.
A. Can I write my diary here?
B. May I use your pencil?
C. Anything else?
D. OK. I will.
E. Be quiet, please!
有理数a、b在数轴上的位置如图所示,下列式子错误的是( )