A) 1. The output seems to have increased. 2. The output is likely to increase. 3. The output proved to have increased. 4. The output is said to have increased.
B)
1. a) This method seems to be efficient. b) This method seems to be simple. c) This method seems to be unknown.
2. a) The system proved to be efficient. b) The system proved to be inefficient. c) The system proved to be good.
C)
1. a) He is known to begin a new experiment. b) He is known to have begun a new experiment.
2. a) He is supposed to obtain interesting data. b) He is supposed to have obtained interesting data.
3. a) He is said to study this phenomenon. b) He is said to have studied this phenomenon.