如果某线性方程组存在两个不同的解，则其定有无穷解。
查看答案
已知某齐次线性方程组只有一个解，则该解一定是零解。
A. 对
B. 错
[音频]Questions 1 and 2 are based on the news report you have just heard.
A. It was held in Las Vegas.
B. It had a large collection of modern computers.
C. Vivint is a smart home service provider.
D. It was said to be the largest collection of new electronic devices in the States.
2
A. The devices might be very expensive.
B. The devices might be stolen when they are not at home.
C. The devices might be hacked and used by someone else.
D. The devices can’t be used when they are far away from home.
[音频]Questions 3 and 4 are based on the news report you have just heard.
A. It caused Prime Minister David Cameron to resign.
B. It caused the global market to rise.
C. It shocked a lot of people.
D. It led to the anti-EU movement.
微信支付 
支付宝支付