2. No one knows about how many elements it is that ________ most of the substances we meet in everyday life.
A. consist of
B. are composed of
C. make up
D. are made up of
(责任编辑:admin) |
2. No one knows about how many elements it is that ________ most of the substances we meet in everyday life.
A. consist of
B. are composed of
C. make up
D. are made up of
(责任编辑:admin) |