下列过程中没有发生化学变化的是[ ]
A．粮食酿酒
B．干冰升华
C．光合作用
D．食物消化
答案：B
公鸡一定不会生蛋，公鸡生蛋的可能性是（ ）
A．1
B．0
C．C、
D．D、
Now the environment in city is _______ than it was before. We should keep it clean. [ ]
A. much better
B. more worse
C. more better
D. much worse
