Wild waterfowl are considered the natural reservoir of all influenza A viruses.野生水鸟是A型流感病毒的天然宿主.Computer systems throughout the country are being affected by a series of mysterious rogue programs, known as viruses...全国的计...
Politicians have debased the meaning of the word "freedom"政客们贬低了“自由”一词的意义。Art has real meaning when it helps people to understand themselves.当艺术有助于人们了解自身的时候才有真正的意义。People use scientific terms with no clear idea of their ...