单项选择题
A．he created wealth for them B．he made cars with all kinds of colors C．his mass production was able to bring the price down D．he produced a gasoline engine as the power for his cars
A．great harm would be done to mankind B．the sea level would go by 10 centimetres C．all the land in the world would be flooded D．crops would be unable to grow on the earth
A．the way in which gases are used for keeping plants warm B．a natural course which is to some degree helpful to us C．the way" greenhouse gases trap heat on the earth D．the whole course in which greenhouse gases prevent heat