4.6.
1) shorter
2)faster
3) much
4)the most expensive
5)more efficient
6)more practical
7)the most popular
8)cheaper
9)more comfortable
10)the best
4.7.
1)bigest
2)largest
3)most important
4)oldest
5)the highest
6)the smallest
7)the most expensive
8) residential
9) the buziest
10) more
11) greatest
12)wealthiest
13) heaviest
14) most famous
15) best