问题补充:
The kid was making noise just to attract attention. Let him be!
A. in addition
B. in vain
C. on average
D. on purpose
答案:
A. in addition
B. in vain
C. on average
(答案→)D. on purpose
解析:考查短语辨析。in addition此外,in vain白费力,on average按平均计算,on purpose故意的,根据句意孩子们故意发出噪音仅仅是引起注意。故选D。