当列车制动后单独缓解机车时，松开单阀手柄，手柄将自动回到制动区的最小减压位。

Scientific surveys conducted during the climbs that Mount Huandoy in Peru      

6395 meters high.

A．shown；is

B．showed；was

C．shows；was

D．showed；is

       was most important to her, she told me, was her family.

A．It

B．This

C．What

D．As

耳鸣渐发如蝉，按之鸣声减轻或暂停者，多因

A．肝胆火盛

B．阴虚火旺

C．气滞血瘀

D．肾精亏损

E．痰湿犯肺

将连续变化的灰度或密度信息转化成离散的数字信息的过程称为

A．采样
B．A/D转换
C．D/A转换
D．量化
E．过滤

下列哪项对明确诊断有帮助：

A．哺乳时下腹疼加剧

B．腹部听诊肠鸣音

C．腹部X线检查

D．血常规检查

E．腹部B超声检查