Matching Pairs LanguageOnline version Idioms by Fernando T. 1 A piece of cake 2 Cost an arm and a leg 3 Butterflies in my stomach 4 My blood is boiling 5 Hit the sack 6 It’s raining cats and dogs 7 In hot water 8 I am under the weather 9 A couch potato To be in difficulties I am very angry! Very expensive Go to sleep! A person who doesn’t have an active life Something that you say when it is raining heavily Very easy! Nervous and anxious I am sick!