Improved medical technology has been one of the spin-offs of the space program

Supplementary information includes adverbs and things that function as adverbs

The vice-president attended the ceremony on behalf of the president

The Vice-President talked at the meeting in place of the President

In English there are eight main parts of speech: noun, verb, adjective, adverb, pronoun, preposition, conjunction and finally interjection

Adverbial time clauses (here 'when') write about the future in the present tense

The Vice-President transmitted the message by radio

Looks, brains, reflexes, rich family and, for good measure, vice president of the student committee - in other words he's 'perfect'

This has visual impairment as a side effect