Problem: Please answer a question about the following article about Electric motor:
Nothing in the principle of any of the motors described above requires that the iron (steel) portions of the rotor actually rotate. If the soft magnetic material of the rotor is made in the form of a cylinder, then (except for the effect of hysteresis) torque is exerted only on the windings of the electromagnets. Taking advantage of this fact is the coreless or ironless DC motor, a specialized form of a PM DC motor. Optimized for rapid acceleration, these motors have a rotor that is constructed without any iron core. The rotor can take the form of a winding-filled cylinder, or a self-supporting structure comprising only the magnet wire and the bonding material. The rotor can fit inside the stator magnets; a magnetically soft stationary cylinder inside the rotor provides a return path for the stator magnetic flux. A second arrangement has the rotor winding basket surrounding the stator magnets. In that design, the rotor fits inside a magnetically soft cylinder that can serve as the housing for the motor, and likewise provides a return path for the flux.
What forms can the rotor take?
A: winding-filled cylinder, or a self-supporting structure
Problem: Please answer a question about the following article about Pesticide:
Since chlorinated hydrocarbon pesticides dissolve in fats and are not excreted, organisms tend to retain them almost indefinitely. Biological magnification is the process whereby these chlorinated hydrocarbons (pesticides) are more concentrated at each level of the food chain. Among marine animals, pesticide concentrations are higher in carnivorous fishes, and even more so in the fish-eating birds and mammals at the top of the ecological pyramid. Global distillation is the process whereby pesticides are transported from warmer to colder regions of the Earth, in particular the Poles and mountain tops. Pesticides that evaporate into the atmosphere at relatively high temperature can be carried considerable distances (thousands of kilometers) by the wind to an area of lower temperature, where they condense and are carried back to the ground in rain or snow.
The movement of pesticides from wawrme to cooler climates is called what?
A: Global distillation
Problem: Please answer a question about the following article about United States dollar:
The U.S. dollar is fiat money. It is the currency most used in international transactions and is the world's most dominant reserve currency. Several countries use it as their official currency, and in many others it is the de facto currency. Besides the United States, it is also used as the sole currency in two British Overseas Territories in the Caribbean: the British Virgin Islands and the Turks and Caicos islands. A few countries use only the U.S. Dollar for paper money, while the country mints its own coins, or also accepts U.S. coins that can be used as payment in U.S. dollars, such as the Susan B. Anthony dollar.
What kind of money is the U.S. dollar?
A: fiat money
Problem: Please answer a question about the following article about 2008 Sichuan earthquake:
Many rescue teams, including that of the Taipei Fire Department from Taiwan, were reported ready to join the rescue effort in Sichuan as early as Wednesday. However, the Red Cross Society of China said that (on May 13) "it was inconvenient currently due to the traffic problem to the hardest hit areas closest to the epicenter." The Red Cross Society of China also stated that the disaster areas need tents, medical supplies, drinking water and food; however it recommended donating cash instead of other items, as it had not been possible to reach roads that were completely damaged or places that were blocked off by landslides. Landslides continuously threatened the progress of a search and rescue group of 80 men, each carrying about 40 kg of relief supplies, from a motorized infantry brigade under commander Yang Wenyao, as they tried to reach the ethnically Tibetan village of Sier at a height of 4000 m above sea level in Pingwu county. The extreme terrain conditions precluded the use of helicopter evacuation, and over 300 of the Tibetan villagers were stranded in their demolished village for five days without food and water before the rescue group finally arrived to help the injured and stranded villagers down the mountain.
What problem continued to stop rescue teams from reaching affected areas?
A:
landslides