—A hot dog , please .
A:are
B:does
C:do
下图为某城市是环形放射状道路,读回答下面小题。
____(凝视,盯着看)at people is considered rude in Britain and young children will be scolded by their parents if they look too long at another person.
氢原子从能级m跃迁到能级n时辐射红光的频率为υ1,从能级n跃迁到能级k时吸收紫光的频率为υ2,已知普朗克常量为h,若氢原子从能级k跃迁到能级m,则( )
如表是某研究小组探究影响反应速率部分因素的相关实验数据.
实验 序号
H2O2溶液浓度/%
H2O2溶液体积/mL
温度/℃
MnO2的用量/g
收集氧气的体积/mL
反应所需的时间/s
①
5
1
20
0.1
4
16.75
②
15
6.04
③
30
35
2
49.21
④
55
10.76