下列关于物态变化的说法,正确的是 [ ]
A.晶体在熔化过程中要不断吸热
B.水在蒸发过程中要不断放热
C.往豆浆中加糖,豆浆会变甜,这是熔化现象
D.冰的形成是凝华现象
答案:A
— How do you deal with the disagreement between the company and the customers?
— The key _____ the problem is to meet the demand _____ by the customers. [ ]
A. to solving ; making
B. to solving ; made
C. to solve ; making
D. to solve ; made
人造地球卫星可在高度不同的圆形轨道上运行,下述判断正确的是( )
A.各国发射的所有人造地球卫星的运动速度都不超过
B.各国发射的所有人造地球卫星的运行周期都不超过
C.若卫星轨道为圆形,则该圆的圆心必定与地心重合
D.地球同步卫星可相对地面静止在北京的正上空