单项选择题
A．A sudden and warm wind. B．Thick and lower clouds. C．Small and feathery cirrus clouds. D．Dark and thunder clouds.
A．learn about the change of weather B．group them and give them names C．tell the differences in clouds D．find the likeness of clouds
A．the weather always remains the same in a day B．a fine day can't last for long C．we rarely think about the weather D．the weather changes a lot