The scientists succeeded in finding a vaccine for that disease. 17/21The scientists succeeded in finding a vaccine for that disease. The scientists were able to find a vaccine for that disease. The scientists were finding a vaccine for that disease. The scientists should have found a vaccine for that disease. The scientists couldn’t find a vaccine for that disease. Giải thíchĐáp án đúng: A Dịch: Các nhà khoa học đã có thể tìm được vắc xin cho bệnh này.