【单选题】
That was a good idea and the government finally_________ it.
【单选题】
Everyone gets older, but you look ______ than ever.
【单选题】
His new book___ next month.
【单选题】
The lives of many people have been enriched_________ adult education.
【单选题】
Adult schools have become popular and the enrollment has_________ rapidly.
【判断题】
若某个线性方程组相应的齐次线性方程组只有零解,则该线性方程组有唯一解。
【判断题】
若X,Y是随机变量,则其数学期望一定有E(XY)=EXEY.
【判断题】
<img src=http://p.ananas.chaoxing.com/star3/origin/7df43063800ce03ac5ba601f7d9c3dd2.png/>
【判断题】
若向量组的秩是r,则其中任意r+1个向量是线性相关的。