问题
选择题
All substances, ＿＿＿＿＿ solids, liquids, or gases, are made up of entirely atoms.
A．whether they
B．whether
C．whether are they
D．whether are
答案
答案：B
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。