A、要约必须是特定人的意思表示                                                                        B、必须具有订立合同的意图                                                                        C、要约必须包括合同的主要内容                                                                        D、内容必须具体确定                                                                        E、要约发出就生效

A、国家的强制力得以体现                                                                        B、契约自由                                                                        C、订立保护，不订立不保护                                                                        D、动态监督