桥涵构造物养护，根据交通发展需要，可通过改造和改建来提高（）和（）。

阅读理解。

    My name is Max. I am twelve years old. I have many friends. Most of them are as old as I. Some are

older. Some are younger.

    My best friend is Bill. He lives near me. We go to the same school and we are in the same class. Bill helps

me with my maths homework. I help him with his English homework.

    Bill is taller than me. He is quite fat. He doesn't like sports, so he doesn't get much exercise. We both have

black eyes, but Bill's hair is longer. I like sports and I play football or go swimming every day. Every Sunday

morning Bill and I play computer games. Sometimes I win. Sometimes he wins.

1. The main idea (主题) of the text is           .[ ]

A. Max has many friends

B. Max and Bill go to the same school

C. Max and Bill are best friends

D. Max and Bill like the same things

2. Most of Max's friends are           . [ ]

A. twelve years old

B. older than Max

C. younger than Max

D. thirteen years old

3. Max and Bill live           . [ ]

A. near each other

B. in different towns

C. in the same house

D. in the school

4. Max helps Bill with           . [ ]

A. his maths homework

B. his English homework

C. His sports lessons

D. His computer lessons

5. Max and Bill both like to           .  [ ]

A. swim

B. play football

C. play computer games

D. play sports

一圆锥侧面展开图为半圆，平面α与圆锥的轴成45°角，则平面α与该圆锥侧面相交的交线为（　　）

A．圆

B．抛物线

C．双曲线

D．椭圆

经验证明，只有不高于______V的电压对人体才是安全的．安全用电的原则是：不靠近______，不接触______．

若某病传统治疗用药疗效较差，平均好转率为50%，今研制新药希望提高疗效，预计平均好转率为70%，需观察例数为η₁，预计平均好转率为80%，需观察例数为η₂则（）

A.η₁<η₂

B.η₁=η₂

C.η₁>η₂

D.需计算检验效能

E.需计算Ⅰ型错误概率

患者男，35岁，左小腿疼痛2天伴发热。查体：左小腿皮肤片状红疹，颜色鲜红，中间较淡，边界清楚，隆起，皮温增高。局部可见硬结、水肿，压痛明显。最可能诊断是（）

A.疖

B.痈

C.急性蜂窝织炎

D.丹毒

E.急性淋巴结炎