1.Jill and Katy _________________________with their class tomrrow
问题描述：
1.Jill and Katy _________________________with their class tomrrow
A\are going to swimming B\are going swimming C\ go to swimming D\go swimming
2.They promised————————————the work in three days
Ato finishB finishingCfinishesDfinished
3.若b+c分之一=1.c+a分之一=1,求b分之ab+1
答
A be going to do sth. 将来做某事
A promise to do sht. 承诺做某事
1
由b+1/c=1
得：b=1-1/c=(c-1)/c,则1/b=c/(c-1),
由c+1/a=1
得：1/a=1-c,则a=1/(1-c),
因此
b/(ab+1)
=a+1/b
=1/(1-c)+c/(c-1)
=1/(1-c)-c/(1-c)
=(1-c)/(1-c)
=1