A 'complete' word is a word in which every letter, in turn, can be replaced by another to form a new word.
For example, SEND is a complete word because:
Starting with SEND we can replace the S with an L to make LEND
Starting with SEND we can replace the E with an A to make SAND
Starting with SEND we can replace the N with an E to make SEED
Starting with SEND we can replace the D with a T to make SENT.
Which 2 of the following words are not complete words? Proper nouns (i.e. people's names) are not allowed.
I travelled at 60mph for 4 hours, which is 240 miles. At 40 miles per gallon this used 6 gallons, which meant the remaining 4 gallons were lost.