依据不同的分类标准,定金合同属于()。
A.双务合同
B.单务合同
C.诺成合同
D.实践合同
E.从合同
参考答案:A, D, E
China develops rapidly in economy,especially in space, draws many western countries’attention.
A.which
B.what
C.it
D.that
______ environmental damage is done, it takes many years for the ecosystem to recover.
A.Even if
B.If only
C.While
D.Once