【单选题】
A: You always enjoy seeing old films, dont you?B: No, not always, but_________ .
【单选题】
If you are tired and_________, you can hardly (几乎不) remember things.
【单选题】
For programs with_________ audiences, the cost of commercials is high.
【单选题】
The experiment_________ in the lab now.
【单选题】
How_________ people do you have in your family?
【单选题】
A traveller was walking _______ the road.
【单选题】
Does jogging cost much? No, it costs almost_________ but a good pair of shoes.
【单选题】
Water_________ both by man and other living things.
【判断题】
非齐次线性方程组Ax=b有解的充要条件是系数矩阵的秩R(A)等于增广矩阵的秩R(A|b).
【判断题】
矩阵的初等行变换不改变矩阵的列向量组的线性相关性和线性组合关系。