双塔式干燥器设（）以使两个干燥塔的电磁阀定时地轮换开、关。 A.继电器 B.控制开关

生理性原因

A．4～12mg
B．5～12mg
C．10～20mg
D．15～40mg
E．50～120mg

试述医疗保险市场中存在的问题，以及他的表现及后果，如何加以控制？ 

流体在紊流粗糙区流动，沿程水头损失的大小随流动速度的变化范围下列说法正确的是（）。

A．沿程水头损失的大小与流动速度的2.0次方成正比

B．沿程水头损失的大小与流动速度的1.75～2.0次方成正比

C．沿程水头损失的大小与流动速度的1.0～2.0次方成正比

D．沿程水头损失的大小与流动速度的1.75次方成正比

语法填空

阅读下面短文, 按照句子结构的语法性和上下文连贯的要求, 在空格处填入一个适当的词或

使用括号中词语的正确形式填空.

     An American inventor, Dean Kamen, says he has invented the worlds first selfbalancing individual

transport vehicle, __1__ is called the Segway Human Transporter.The Segway looks like a long stick

__2__ two wheels.The stick has handles for a person __3__(hold)．The wheels are connected by a

platform.The person stands on the platform and holds __4__ handles.The vehicle moves forward or

backward __5__ the person moves his body in that direction.The driver turns the handles __6__(go)

left or right.The Segway has computers and gyroscope devices to make __7__ move and balance.It is

powered by batteries that can be recharged in a few hours by __8__(use) an electric outlet.It can travel

at a speed of nineteen kilometers per hour.It costs less than ten cents a day to operate.It does not

produce pollution.Mister Kamen says the Segway could replace cars in __9__(crowd)city centers.He

says it was designed to reduce pollution and solve other __10__(environment)problems in cities.

However, it was not designed to travel on roads.

下列适用于无执照驾驶的情况是（）？

A.带有罚金缴纳通知单驾驶的时候

B.收到颁发的驾驶执照后进行驾驶的时候

C.在受到停止驾驶处分的期间进行驾驶的时候

D.持有临时驾驶进行驾驶的时候