教师偏爱优等生，不会对师生关系造成影响。
参考答案：错
Let's go and have ______ her family photo. [ ]
A. a look
B. look at
C. a look at
D. the look at
已知a，b为常数，若f（x）=x2+4x+3，f（ax+b）=x2+10x+24，则5a-b=（）。
