4 a Form words using -en, in-, -ion, re-. 1 dark ................................................ (v) 2 furnish ........................................... (v) 3 intent .............................................. (n) 4 experience ..................................... (n) 5 perfect ............................................. (n) b Use the words from Ex. 4a in the correct form to complete the sentences 1-5. 1 His ......................... in sailing was proven to be the cause of the accident. 2 You'll have to come and see my flat. I've just ......................... it. 3 Large grey clouds suddenly ......................... the sky above us. 4 This is such an excellent meal! It's cooked to .........................! 5 It wasn't his ........................., but he caused a lot of trouble.