1.In 2021, the team created Winter Olympics-themed shadow pupets. The troupe also staged different plays ___9___ (introduce) ice and snow sports through fairy tales.
想请教各位老师,这里的第9空填introducing和to introduce是不是都可以呢?
2.And are the viruses infecting (infect) us today going to have an impact on our evolution in the future? “Of course! The answer is why not?” laughs Mita. But it will be many generations ___18___ we can look back and say this evolution has happened.
这个18空before和until是不是都可以呢?