19．听第15段材料，回答第19至第22题．
19．Who are the speakers？
A．Pen pals．
B．Mother and son．
C．Teacher and student．
20．How can Mike improve his pronunciation？
A．By watching TV．
B．By listening to tapes．
C．By singing songs．
21．When does the English club meet？
A．On Wednesday．
B．On Thursday．
C．On Friday．
22．What should Mike do with writing practice？
A．Find a pen pal．
B．Join a club．
C．Write to newspapers．
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