题目1A. 若<img src="https://tihai-oss-cloud.itihey.com/img/54f4567d5d1aa85ddf2c5f3ce75ecf98.png">中有一个<img src="https://tihai-oss-cloud.itihey.com/img/3976cccc520a3071d27c821c613bb6ea.png">阶子式不为零,则<img src="https://tihai-oss-cloud.itihey.com/img/a60532ae11a1ee987074f4f4928e967e.png">B. 若<img src="https://tihai-oss-cloud.itihey.com/img/54f4567d5d1aa85ddf2c5f3ce75ecf98.png">中有一个<img src="https://tihai-oss-cloud.itihey.com/img/3976cccc520a3071d27c821c613bb6ea.png">阶子式不为零,则<img src="https://tihai-oss-cloud.itihey.com/img/e612c89a3a0515719a8466d9ffa8915a.png">C. 若<img src="https://tihai-oss-cloud.itihey.com/img/54f4567d5d1aa85ddf2c5f3ce75ecf98.png">中所有<img src="https://tihai-oss-cloud.itihey.com/img/3976cccc520a3071d27c821c613bb6ea.png">阶子式全为零,则<img src="https://tihai-oss-cloud.itihey.com/img/ecb57841904002feaf1d3cfb478c3358.png">D. 非零矩阵的秩至少等于1