【简答题】A.No one knows exactly how silk was made. B.No one knows exactly when silk was made. C.The history of the silk is a fascinating story. D.The Chinese people kept the secret of how to make silk for as l...
【简答题】______ is the amount of heat necessary to raise the temperature of exactly one gram of a material by exactly one degree (1℃ or 1K). A) Heat capacity B) Specific heat C) Thermal conductivity D) Coeffi...
【简答题】阅读理解 No one knows exactly how many disabled people there are in the world, but estimates (估计) suggest the figure is over 450 million. The number of disabled people in India alone is probably more th...