— Yes. They are my good friends.
A:How lovely
B:What lovely
C:What a lovely
D:How a lovely
①求冰块的体积V.
②若冰块吸热后,有2×10-3m3的冰融化成水,求水的质量m.
利用图甲所示器材“探究二力平衡的条件”.
设fx=ex+x-4,则函数fx的零点位于区间( )