49. People know that students wanted to learn online. A. It was known that students wanted to learn online. C. Students are known to have wanted to learn online. 50. The teacher was too strict, so I felt nervous in his lesson. A. If the teacher were not too strict, I wouldn't feel nervous in his lesson. B. If the teacher had been too strict, I wouldn't have felt nervous in his lesson. C. If the teacher is not too strict, I will not feel nervous in his lesson. D. If the teacher had not been too strict, I wouldn't have felt nervous in his lesson. B. It is known to have wanted to learn online. D. Students are known to want to learn online.