问题如下：
Cash received in advance is a :
选项：
A. revenue&asset
B. assset&liability
C. revenue&equity
解释：
B is correct. Cash received in advance is unearned revenue. It is a liabilities bacause the product or service have not delivered.It is an asset bacause cash have already received.
如果题目换成cash payable，那么选项还是asset和liability吗？
