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