A:都可存在于内环境中
B:与细胞膜上的受体结合才能发挥作用
C:由核糖体合成,经内质网、高尔基体分泌到细胞外
D:在不同人体内种类各不相同
《明天不封阳台》是____,代表作____、____。
质量为1 kg的小球从空中某处自由下落,与水平地面相碰后弹到空中某一高度,其速度随时间变化的关系如图所示,取g=10 m/s2,则 ( )
Hearing the good news that he had been admitted into his dream university after so many years of hard work, his parents couldn't help b____ into tears.