题目4单选题
交换积分次序<img src="https://tihai-oss-cloud.itihey.com/img/a988aa6c77b3b5a5a5b3c02c3dd00bab.png">( )A. <img src="https://tihai-oss-cloud.itihey.com/img/41cd3b4185c3f3517f7f21d5b474778f.png">B. <img src="https://tihai-oss-cloud.itihey.com/img/806d8677219ffa3826c5bc314763056b.png">C. <img src="https://tihai-oss-cloud.itihey.com/img/897a2d0e2951c95eded221d66354d6c3.png">D. <img src="https://tihai-oss-cloud.itihey.com/img/0ef95bad9b5264aa467129626a1ac15f.png">