半径为a的无限长导体圆柱单位长度的内自感应为（）H。 A. B. C. D.

请将饮食中应注意的内容的编号填入前面相应病症的括号内：

(    )①牙龈经常出血的人                 

A．多吃含铁和蛋白质丰富的食物

( )②患了贫血的人

B．吃加碘盐或多吃海带、紫菜等

( )③患了骨质疏松症的人

C．多吃含钙多的食物

( )④饮食中长期缺碘的人

D．多吃富含维生素C的蔬菜和水果(    )⑤不爱吃菜经常便秘的人             E．平时应多补充蛋白质

(    )⑥骨折的病人                       F．多吃富含膳食纤维的蔬菜和水果

阅读理解。

                                             Student Membership-Cambridge Arts Cinema

     Cambridge Arts Cinema is one of the art houses in Britain and home of the internationally celebrated

Cambridge Film Festival. Since 1947 generations of students have discovered the wealth of world cinema.

Now you too can make most of it and save money.

1. Which of the following is the most famous event held at Cambridge Arts Cinema?

A. The Cambridge Film Festival.

B. Meetings with filmmakers.

C. The preview screening.

D. Monthly premieres.

2. If you're a member of Cambridge Arts Cinema, you will enjoy free _____. 

A. Darkroom Gallery shows

B. mailed programmes

C. special film events

D. film shows

3. How long will the membership for Cambridge Arts Cinema last?

A. Four months.

B. Eight months.

C. Nine months.

D. One year.

4. For what purpose is the text written?

A. Offering students cheaper tickets.

B. Announcing the opening of a premiere.

C. Telling the public of the cinema's address.

D. Increasing the cinema's membership.

男性，68岁，2周前曾发生急性心肌梗死，现出现心前区跳动性疼痛，闻及心包摩擦音，肌钙蛋白正常，治疗首选（）

A.异烟肼

B.阿司匹林

C.糖皮质激素

D.地高辛

E.呋塞米

论述我国城市产业结构的现状以及优化途径？

笛卡尔的哲学与其他哲学的不同就是（）。