像素深度即像素所有颜色分量的二进位数之和。黑白图像的像素深度为（）。
参考答案：1
A communicative satellite ______ as much as 3.5 tons was sent up into space last week.
A．weighing
B．weighed
C．to be weighed
D．being weighed
建立社会保障制度是建立社会主义市场经济的要求。 ( )
