All substances, ＿＿＿＿＿ solids, liquids, or gases, are made up of entirely atoms.
A. whether they
B. whether
C. whether are they
D. whether are
网友回答
A. whether they
(答案→)B. whether
C. whether are they
D. whether are
解析：在带有状语从句的复合句中，如果从句与主句的主语一致，且从句中含有be动词，则可以省略从句的主语及be动词。此处从句中省略了they are。