榴莲被誉为“果中之王”.切开榴莲时可闻到特殊香味,这说明( )
A:分子质量很小
B:分子体积很小
C:分子在不断运动
D:分子间有间隔
读短文,填空
Hello ! My name is Amy .I'm a girl .I'm from England. Look !This is my father and this is my mother .My father is a teacher. My mother is a doctor .The boy is my brother .He's eight .He's a student .who's this girl ? Can you guess??
=75-30
=45
若已知某行星绕太阳公转的半径为r,公转的周期为T,万有引力常量为G,则由此可求出( )