練習(xí)一 

present;since;doctor; 

pollution;open; 

D;A;B;A;C;B;B;AD;B; 

wastaught;married; 

swim;came;havebeen; 

havelived;was. 

練習(xí)二 

changes;seen;infact; 

marry;southern;hadfun; 

won'tuntil;havebeenmarried; 

haskept;differentfrom 

AADBDABB 

練習(xí)三

possible;service;althgough; 

attraction;present;have; 

since;Howmany;Whenbuy; 

Havecarried;been;hasn't;sad;去掉 

but;yet;nextto; 

hasbeenopened;anylonger;howtoget; 

It'storead;Itiscame; 

butcame;haveknown;arefondof 

練習(xí)四 

CBACCB;notarrived;yet;Howlong;heard;Haseverbeen;Haschanged;yet; 

IhavelivedheresinceIwasborn. 

It'spleasanttoplayChinesechesswithmyclassmates. 

AlthoughTomwasill,hewenttoschool. 

WhereisMarry?Shehasgonetothecinema; 

HaveyoubeentoBeijing?YesIhave. 

Iusedtoplaycomputergames,nowIdon'tdoit.