题目5单选题
<img src="https://tihai-oss-cloud.itihey.com/img/01cb78f6ac952694c4fbb3ec8f423bc2.jpg">和<img src="https://tihai-oss-cloud.itihey.com/img/d1e62b787e072105c5733e8a626a2d71.jpg">均是原子命题,"如果<img src="https://tihai-oss-cloud.itihey.com/img/61f40ffd5929f74e54ce4487682ceaed.jpg">那么<img src="https://tihai-oss-cloud.itihey.com/img/ea5ab2be19cf84019bb394d90f32536e.jpg">"是由<img src="https://tihai-oss-cloud.itihey.com/img/00ec12c71411a56b48b2301a4e70736b.jpg">和<img src="https://tihai-oss-cloud.itihey.com/img/415770c68d7b0d720fb70400857fd9c7.jpg">组合得到的复合命题.下面对"如果<img src="https://tihai-oss-cloud.itihey.com/img/700d813da8b16172bbdf15aadd0896f4.jpg">那么<img src="https://tihai-oss-cloud.itihey.com/img/240ace2bcded748eb342cce5496166b4.jpg">"这一复合命题描述不正确的是( )A. "如果<img src="https://tihai-oss-cloud.itihey.com/img/be38bba0829b60306da6b256a1be1459.jpg">那么<img src="https://tihai-oss-cloud.itihey.com/img/046979b3b7517ca11717629f6f8ed8b1.jpg">"定义的是一种蕴涵关系(即充分条件)B. "如果<img src="https://tihai-oss-cloud.itihey.com/img/233a362994ca305902694191a1795fd1.jpg">那么<img src="https://tihai-oss-cloud.itihey.com/img/9702f45a6787ed458655660a68d23113.jpg">"意味着命题<img src="https://tihai-oss-cloud.itihey.com/img/a3d98c1abf22cce0a288174a14ec9be2.jpg">包含着命题<img src="https://tihai-oss-cloud.itihey.com/img/fc4ae16c36907b9472407d0d3c9b85aa.jpg">,即<img src="https://tihai-oss-cloud.itihey.com/img/d202c30377c8b2473f393a434771fd25.jpg">是<img src="https://tihai-oss-cloud.itihey.com/img/648f2d8903d3d54319ab1bec55de1121.jpg">的子集C. 无法用真值表来判断"如果<img src="https://tihai-oss-cloud.itihey.com/img/fe48f4154b2a9fa485225adbff96d95c.jpg">那么<img src="https://tihai-oss-cloud.itihey.com/img/dca9a1f24361c526e9ea36c6811fd9ec.jpg">"的真假D. 当<img src="https://tihai-oss-cloud.itihey.com/img/9a0f23737b03aebf8904ef71740fed43.jpg">不成立时,"如果<img src="https://tihai-oss-cloud.itihey.com/img/db28aa913bf2bf00b96922acb07d218e.jpg">那么<img src="https://tihai-oss-cloud.itihey.com/img/5f766d46f5b212c8feef3c72bfc2012a.jpg">"恒为真