50.His father is working.
His father is ______ _______
答案:1.Make sure
2.when to 3.none of 4.without saying 5.didn'her nor has
7.spent writing(on) 8.should be knocked 9.cost her 10.Why not 11.if/whether
would 12.instead of 13.population larger 14.of importance 15.unless runs
16.have repaired 17.so do 18.thick for skate on 19.What is 20.is held 21.It's
said 22.reading better 23.would go 24.
usual 26.to have 27.too
for to reach 28.is interesting to 29.nothing before/her/nor did37.him singing 38.heitht as 39. give up 40.keep clean 41.kept
staying 42.less 43.population larger that 44.not about 45.taught himself
46.only 47.is bad 48.be covered 49.was cheap enough 50.at work