6、. A.at B.of C.for D.in()15.They don’t have Chinese ______ maths on Tuesday. A. and B. butC. or D.also()16.What about ______in the morning? A. swim B. swiming C. swimming D.toswim()17.We have a break ____ talk _____our friends. A and , in B. but , of C. and ,toD.but,in( )18.Linda