单项选择题
A．no other country can make one like it B．it is much cheaper to operate C．it is more sophisticated than Landsat 7 D．Terra will show energy gains
A．People are more likely to catch cold in the winter. B．Colds are so common that even the strongest person cannot avoid it. C．Old people are likely to catch cold because they are unpleasant. D．Colds can never be cured without the help of medicin
A．Black stands for unhappiness. B．Black makes people think of night. C．Black makes people think of sorrow. D．Black is the color of the mournin