多项选择题
A new technique (), the yields as a whole increased by 20 percent
A. working out B. having worked out C. having been worked out D. to have been worked out
多项选择题 I learned how to () a bicycle when I was six years old.
多项选择题 It looks () the family has got a lot of problems
多项选择题 The next few days could be()for the peace negotiation.
