药品通用名称应当（） A.印刷在药品标签的边角 B.为起算月份对应年月的前1个月 C

比一比，再组词语。

扭（　　）恬（　　）博（　　）端（　　）

纽（　　）甜（　　）搏（　　）瑞（　　）

如图反映的这一历史现象出现于

A．三国时期

B．南北朝时期

C．明朝时期

D．清朝时期

如图所示，一个质量为m=2.0×10^-11kg，电荷量q=+1.0×10^-5C的带电微粒（重力忽略不计），从静止开始经U₁=100V电压加速后，水平进入两平行金属板间的偏转电场中，上板带正电．金属板长L=20cm，两板间距d=10

3

cm．求：

（1）微粒进入偏转电场时的速度v₀是多大？

（2）若微粒射出偏转电场时的偏转角为θ=30°，并接着进入一个方向垂直于纸面向里的匀强磁场区，则两金属板间的电压U₂是多大？

（3）若该匀强磁场的宽度为D=10

3

cm，为使微粒不会由磁场右边界射出，该匀强磁场的磁感应强度B至少多大？

Chang' e-2 was launched successfully on Oct l, 2010  _____ the hard work of scientific and

technological workers in Aeronautics.    [ ]

A. in spite of                    

B. due to    

C. along with                      

D. rather than

Until recently, scientists knew little about life in the deep sea, nor had they reason to believe that it was being threatened. Now, with the benefit of technology that allows for deeper exploration, researchers have uncovered a remarkable array of species inhabiting the ocean floor at depths of more than 660 feet, or about 200 meters. At the same time, however, technology has also enabled fishermen to reach far deeper than ever before, into areas where bottom trawls can destroy in minutes what has taken nature hundreds and in some cases thousands of years to build. Many of the world’s coral species, for example, are found at depths of more than 200 meters. It is also estimated that roughly half of the world’s highest seamounts—areas that rise from the ocean floor and are particularly rich in marine life—are also found in the deep ocean. These deep sea ecosystems provide shelter, spawning and breeding areas for fish and other creatures, as well as protection from p currents and predators. Moreover, they are believed to harbor some of the most extensive reservoirs of life on earth, with estimates ranging from 500,000 to 100 million species inhabiting these largely unexplored and highly fragile ecosystems.Yet just as we are beginning to recognize the tremendous diversity of life in these areas, along with the potential benefits newly found species may hold for human society in the form of potential food products and new medicines, they are at risk of being lost forever. With enhanced ability both to identify where these species-rich areas are located and to trawl in deeper water than before, commercial fishing vessels are now beginning to reach down with nets the size of football fields, catching everything in their path while simultaneously crashing fragile corals and breaking up the delicate structure of reefs and seamounts that provide critical habitat to the countless species of fish and other marine life that inhabit the deep ocean floor.Because deep sea bottom trawling is a recent phenomenon, the damage that has been done is still limited. If steps are taken quickly to prevent this kind of destructive activity from occurring on the high seas, the benefits both to the marine environment and to future generations are incalculable. And they far outweigh the short-term costs to the fishing industry.