下列哪种尘埃对人体最有害（） A.石棉尘 B.面粉 C.沙尘

一个PIIS的主要部件由显示模块、（）、供电模块组成。

（2012•福建）一卫星绕某一行星表面附近做匀速圆周运动，其线速度大小为v．假设宇航员在该行星表面上用弹簧测力计测量一质量为m的物体重力，物体静止时，弹簧测力计的示数为N．已知引力常量为G，则这颗行星的质量为（　　）

A．

B．

C．

D．

阅读理解

TUESDAY, July11

   SHANGHAI-The 12th International Processing, Packaging & End-Line Printing Exhibition opens at

Shanghai New International Expo Centre ( to July 13)

   Tel: 021 6209 5209

   HONGKONG-The Hong Kong International Textile and Garment Machinery and Technology Fair

2006 opens at Hong Kong Convention and Exhibition Centre ( to July 14).

   Tel: +852 2584 4333

THURSDAY, July 13

   SHANGHAI-The China(Shanghai) International Wedding Photographic Equipment Exhibition (Autumn) opens at Shanghai Mart ( to July16 ).

   Tel: 021 6272 2828

   HARBIN, Heilongjiang Province-The Ninth Harbin International Automobile Industry Exhibition and

Sports Centre ( to July 17 ).

   Tel : 0451 5363 5464

FRIDAY, July 14

   HONG KONG-The Hong Kong Wedding, Banquet & Wedding Accessories Expo 2006 opens at

Hong Kong Convention and Exhibition Centre ( to July 16 ).

   Tel: +852 2367 8385

WEDNESDAY, July 19

   SHANGHAI-The 14th Shanghai International Advertising Technology & Equipment Exhibition / Shanghai International Media Technology & Equipment opens at Shanghai New International Expo Centre ( to

July 22 ).

   Tel: 021 6328 8899

   SHANGHAI-The Shanghai International Outdoor AD Illuminating Technology & Equipment Exhibition, Outdoor Media Promotion Exhibition opens at Shanghai New International Expo Centre ( to July 22 ).

   Tel: 021 6321 7522

   SHANGHAI-PAPERTECH Shanghai 2006 opens at Shanghai New International Expo Centre ( to

July 22 ).

   Tel: 021 6328 8899

1 . More exhibitions are held in _______

A . Shanghai New International Expo Centre

B . Hong Kong Convention and Exhibition Centre

C . Shanghai Mart

D . Harbin International conference, Exhibition and Sports Centre

2 . How many exhibitions can you attend on July 15______

A . one    

B . two    

C . three    

D . four

3 . The text is likely to be a (an)________

A . business diary

B . product advertisement

C . private timetable

D . magazine

男．20岁，低热、盗汗、咳嗽、血痰一月。胸片示右上肺小片状浸润影，密度不均。确诊应选择的检查是（）

A.PPD试验

B.痰TB-DNA

C.血清中结核抗体

D.痰检抗酸杆菌

E.血沉

焊接裂纹是焊接缺陷中危害最大、不允许存在的焊接缺陷。