What does a “friend for a season” mean?
A. Someone who is good at making you laugh.
B. Someone who teaches you how to have fun.
C. Someone who will stay in your life for a short time.
D. Someone who comes into your life only for fun.
查看答案
What is a lifetime friend?
A. Someone who always helps you out of difficulties.
B. Someone who understands you better than anyone else.
C. Someone who has experienced hardships with you.
D. Someone who together with you makes up a single soul in two bodies.
What is the passage mainly about?
A. Three different stages of friendship.
B. Three different types of friendship in our life.
C. Three different ways of getting along with people.
D. Three different lessons on how to be good to your friends.
5．若A为6阶方阵，齐次方程组Ax=0基础解系中解向量的个数为2，则r(A)（）
A. 2
B. 3
C. 4
D. 5
设A为n阶方阵，r(A)
Ax=0只有零解
B.Ax=0的基础解系含r(A)个解向量
C.Ax=0的基础解系含n-r(A)个解向量
D.Ax=0没有解
微信支付 
支付宝支付