题目4单选题
7.已知<img src="https://tihai-oss-cloud.itihey.com/img/2e51e2e3f84054360299f2c480d677b4.png">,下列各式表达正确的是( )A. <img src="https://tihai-oss-cloud.itihey.com/img/5f8036e0cef2dc17c68d720468f6c456.png">B. <img src="https://tihai-oss-cloud.itihey.com/img/7a916a99e8e3c789499c94877e3ef477.png">C. <img src="https://tihai-oss-cloud.itihey.com/img/1adc2186b7062b6d3d0f3935d4ff771e.png">D. <img src="https://tihai-oss-cloud.itihey.com/img/8e2e0dfb7fb158a5bacc0c9bd3a822e9.png">