Yesterday I a Christmas tree.[ ]
A. bought
B. buy
C. am going to buy
答案：A
方程3x3-24=0的根是______．
图中a、b、c、d是四个将有等量、等温水的相同容器，容器放入电阻丝，Ra、Rb、Rc、Rd，且Ra=Rc＜Rb=Rd，如图所示，问经过相同的时间，四个容器水温从高到低的顺序是______．
