听力原文:(A) A waiter is taking their order. (B) A woman is drinking a cup of coffee. (C) A woman is carrying a tray of desserts. (D) A woman is waiting to place her order.
A.
B.
C.
D.
手机使用
分享
复制链接
新浪微博
分享QQ
微信扫一扫
微信内点击右上角“…”即可分享
反馈
参考答案:
举一反三
【判断题】A triangular matrix is invertible if and only if no diagonal entries are zero.