但因赠与合同系单务、无偿合同，所以为维护赠与人的利益，法律应于特殊情形下，允许赠与人撤销赠与。

But the gift contract is a unilateral and gratuitous contract. So to protect the donator's benefit the Law should allow the donator to have the right of revocation in some special situation.

youdao

按形式分，合同有双务和单务两种。

If we classify contracts by their forms, they are either bilateral or unilateral.

youdao

按形式分，合同有双务和单务两种。

If we classify contracts by their forms, they are either bilateral or unilateral.

youdao