单项选择题

For mankind, the sun is the source of（）

A．solar activity
B．all heat
C．all food
D．both B and C

<上一题 目录 下一题>
热门 试题

单项选择题
All the useful energy at the surface of the earth comes（）

A．directly from the sun
B．from the sun' s activity
C．from energy stored by the sun
D．from radiation of the sun
单项选择题
The sun' s energy indirectly provides the earth with （）

A．fuels
B．waterpower
C．light
D．both A and B
相关试题