1. His
experiments are (more interesting) than ours.
2. It is one of the (most difficult) problems.
3. The results of this last experiment were (better) than before.
He has got the (best) results this time.
4. The illumination of the Earth by the Sun is (stronger) than that by Sirius,
the (brightest) star of the northern hemisphere.
5. Mercury is the (hottest) place in the solar system.