11. The older generation often reminisces about the ____________ days of their youth.
a) warmer
b) harder
c) lighter
d) slower
12. The athlete found that training at high altitudes improved his ____________ endurance.
a) fast
b) higher
c) darker
d) warmer
13. The ____________ the fabric, the more comfortable the sofa felt.
a) softer
b) darker
c) harder
d) older
14. The ____________ the music, the more vibrant the atmosphere became.
a) older
b) slower
c) louder
d) warmer
15. The ____________ the days passed, the more she longed for her family.
a) older
b) lighter
c) faster
d) poorer
16. The __________ the temperature, the more uncomfortable it gets in winter.
a) colder
b) warmer
c) colder, warmer
d) older
17. As you climb the mountain, the air becomes thinner, and the temperature gets __________.
a) higher
b) lower
c) colder
d) darker
18. The __________ you go into the cave, the less visibility you have.
a) darker
b) higher
c) lighter
d) harder
19. With each passing year, the technology becomes more advanced and the devices get __________.
a) faster
b) older
c) slower
d) taller
20. The ice cream melted quickly in the __________ summer sun.
a) hot
b) cold
c) dark
d) soft
21. The river flows __________ as it descends from the mountains.
a) slower
b) warmer
c) colder
d) higher