In each row, find a 3-letter word whose letters, in some order, can also be used to complete the 7-, 6-, 5-, and 4-letter words.
1. a-s--th , r-b-o- , -as-- , ---d , ---
2. -o-g-en , -ia--s , -o-c- , ---g , ---
3. r--l-ct , b-r--t , --v-r , b--- , ---
4. bo--n-t , -hac-- , a---e , -n-- , ---
-5. st-n--y , -e-l-m , -r-i- , --l- , ---