设 λ=0 是n阶方阵A的特征值,则方程组 Ax=0 有非零解. ( )
查看答案
By the end of this year, we surely ____ a satisfactory solution to the problems.
A. have found
B. will be finding
C. will have found
D. are finding
Not knowing what to do next, _____ his friends for advice.
A. will he go to
B. he is going to
C. did he go to
D. he went to
The mayor who was won the election ____ on television next week.
A. be to speak
B. is to speak
C. is speaking
D. to speak
Great changesin the last few years.
A. have taken place
B. have been taken place
C. were taken place
D. took place
微信支付 
支付宝支付