多层螺旋CT的发明是在第三代CT的基础上进行的，采用了滑环技术。下列描述错误的是

A．X线管连续旋转

B．连续进床

C．连续曝光

D．连续采集

E．采用低热容量球管

In the following essay, each blank has four choices. Choose the best answer and write down on the answer sheet.

In low-speed network, it is usually adequate to wait for congestion to occur and then react to it by telling the source of packets to slow down. In high-speed networks, this approach often works poorly, because in the (71) between sending the notification and notification arriving at the source, thousands of additional (72) may arrive. In ATM network, a major tool for preventing (73) is (74) control. When a host wants a new virtual (75) , it must describe the traffic to be offered and the service expected.

75（）

A．path

B．rout

C．circuit

D．way