PONS词典中的例句（已经编辑处理）
单语范例（未经PONS编辑处理）
The investigation team found no trace of the virus in either case.
en.wikipedia.org Scientists have not determined exactly when the change or mutation occurred, but the effects of vaccinia and cowpox virus as vaccine are nearly the same.
en.wikipedia.org Three of these genes, "gag", "pol", and "env", contain information needed to make the structural proteins for new virus particles.
en.wikipedia.org This does not occur because of a bug in the virus code.
en.wikipedia.org The virus is out, and thousands of lives are on the line.
en.wikipedia.org