Answers
1. cumulus ⇒ b. look like pieces of cotton in the sky
2. altostratus ⇒ c. resembles an overcast sky; layers of gray or white clouds
3. cirrus ⇒ a. look like wispy feathers high in the sky
4. nimbostratus ⇒ E.dark, thick-layered clouds; rain's coming
5. fog ⇒ d. clouds nearest Earth's surface