1. If you go ___ doing that and you'll end ____ in serious trouble. A.on - with. B.on - up. C.off - with. D.out - up 2. They arr trying to save the animals ____ extinction. A.on. B.to. C.from. D.for 3. They didn't see each other again ___ the fall. A.since. B.in. C.from. D.until 4.____ari is one of the many problems we have to solve A.pure. B.polluted. C.fresh. D.pleasant 5. People have ___ this beach with a lot of trash A.spoiled. B.cleaned. C.collected. D.pleasant Giúp với mai mình thi rồi