Have you ever imagined a world famous person like Einstein A: ecome B: to become C: ecoming D: ecame

If the kids stay indoors all the time and get no exercise, they _________ weak. A: ecome B: have become C: will become D: ecame

Now the pollution caused by increasing number of cars ___________ more and more serious in many cities. A: ecome B: ecame C: is becoming D: had become