Make up sentences using the following words:
1. Hard, work, must, to, well, learn, one.
2. Your, does, tell, friend, about, you, studies, him, meet, you, when?
3. Tomorrow, club, at, the, lecture, his, Prof. Smith, deliver, not, will.
4. Scientific, great, many, were, there, century, discoveries, 20th, the, in.

1. One must work hard to learn well. 2. Does your friend tell you about studies when you meet him? 3. Prof. Smith will not deliver his lecture at the club tomorrow. 4. There were many great scientific discoveries in the 20th century.