A:a→b→c→d
B:c→a→b→d
C:a→c→d→b
D:c→a→d→b
A B C
D E.
①____ ②____ ③____ ④____ ⑤____
某物质加热分解产生氧化铜和水。则该物质含有的全部元素是 ( )
Our English ______ far better in a month if we try harder.