-- ______do millions of online users visit the home page of the government?

-- To read the news and search for the information they need.

A．When

B．Where

C．Why

D．What

用滑轮组在竖直方向提起重物，要求拉力是物重的．且拉力的方向向下，请在如图所示的方框中画出滑轮组的绕法(不计动滑轮重、绳重及摩擦，要求滑轮的个数为最少)．