【单选题】听力原文: In recent years, linguists(语言学家) and language teachers have begun to describe language according not only to grammatical structure, using traditional concepts and terms such as the imperative, b...
【简答题】Scientists Alan M.Goldberg and Thomas Hartung describe recent advances in replacing the use of animals in toxicology(毒物学)testing.Improvements in cell and tissue culture technologies,for example,allow ...