尿常规可检查的项目是（） A.尿糖定量 B.尿蛋白 C.尿结核菌 D.尿酸碱度 E.

阅读理解。

     Leonardo da Vinci was one of the world's greatest men.  He was born in Italy in 1452 and died in

1519. He was a great artist and scientist.  He invented many things. He studied the body and how plants

grow. He drew the first aircraft. He also drew a ship that could go under the sea.

     Other clever inventors, such as Benjamin Franklin and Thomas Edison, also invented things, but they

were not artists at the same time. They didn't paint great paintings.

      Leonardo painted one of the most famous paintings in the world.  It is called The Mon,a Lisa, and

we can still see it in Paris, France now.  The Mona Lisa is a painting of a woman. Leonardo also painted

another of the world's greatest paintings-The Last Supper.

1. The Mona Lisa was______. 

A. Leonardo's mother    

B. Leonardo's friend

C. No one knows.      

D. the title of a famous painting

2. Leonardo da Vinci was different from Thomas Edison because______.

A. Edison was an Italian          

B.  Edison was a scientist

C. Leonardo was not an inventor    

D. Leonardo was also a scientist and artist

3. When Leonardo died, he was______.

A. 52 years old    

B. more than 60 years old

C. over 70 years old    

D. only 50 years old

4. Which is a famous painting by Leonardo da Vinci?

A. The last supper.    

B. Mona Lisa's Mother.

C. The last meal.    

D. The first aircraft.

5. The main idea of the passage is about______.

A. a famous Italian artist    

B. Thomas Edison

C. a famous scientist      

D. a great artist and inventor

如图，一光滑水平桌面AB与一半径为R的光滑半圆形轨道相切于C点，且两者固定不动．一长L为0.8m的细绳，一端固定于O点，另一端系一个质量m₁为0.2kg的球．当球在竖直方向静止时，球对水平桌面的作用力刚好为零．现将球提起使细绳处于水平位置时无初速释放．当球m₁摆至最低点时，恰与放在桌面上的质量m₂为0.8kg的小铁球正碰，碰后m₁小球以2m/s的速度弹回，m₂将沿半圆形轨道运动，恰好能通过最高点D．g=10m/s²，求：

（1）m₂在圆形轨道最低点C的速度为多大？

（2）光滑圆形轨道半径R应为多大？

已知难溶电解质在水溶液中存在溶解平衡：M_mA_n(s)mMⁿ⁺(aq)＋nA^m-(aq)，Ksp＝[Mⁿ⁺]·[A^m-]n，称为溶度积。某学习小组欲探究CaSO₄沉淀转化为CaCO₃沉淀的可能性，查得如下资料：(25℃)

实验步骤如下：

①往100 mL 0.1 mol·L^-1的CaCl₂溶液中加入100 mL 0.1 mol·L^-1的Na₂SO₄溶液，立即有白色沉淀生成。

②向上述悬浊液中加入固体Na₂CO₃ 3g，搅拌，静置，沉淀后弃去上层清液。

③再加入蒸馏水搅拌，静置，沉淀后再弃去上层清液。 

④_________________________。

(1)由题中信息Ksp越大，表示电解质的溶解度越______(填“大”或“小”)。

(2)写出第②步发生反应的化学方程式：__________________________。

(3)设计第③步的目的是____________________。

(4)请补充第④步操作及发生的现象：__________________________________。

室内排水用附件主要有（）。

A.存水弯

B.疏水器

C.检查口

D.通气帽

急性尿潴留最常见的原因是（）

A.下尿路梗阻

B.神经源性膀胱

C.药物性因素

D.精神性因素

E.以上都不是