offer and absolute and unqualified acceptance 要约和绝对接受
consensus ad idem 意思表示一致，也叫meeting of minds
intention to create legal relations 建立合同关系的意愿
genuineness of consent 同意的真实性
contractual capacity of the parties 合同当事人的缔约能力
legality of object 标的物的合法性
possibility of performance 履行的可能性
certainty of terms 条款的确定性
valuable consideration 等价有偿
contract object 标的
quantity 数量
quality 质量
price or remuneration 价款或者报酬
time limit 履行期限
liability for breach of contract 违约责任
methods to settle disputes 解决争议的方法