--Isairthelightestthingintheworld?  --Not           .Sc...

问题详情：

-- Is air the lightest thing in the world?

   -- Not            . Scientists from Zhejiang University have just developed the world’s lightest material.

    A. now      B. yet      C. then         D. again

【回答】

A

知识点：副词

题型：选择题