12 Words for everyday situations and for certificate tests

TOEFL Vocabulary #2

Gas given off during a chemical reaction; may or may not have an odour. Sign of a chemical reaction.

(v.) to do a favor or service for, help out; to provide for, supply with; to have space for; to make fit or suitable.

people of the same age who share similar interests

(n.) something that makes movement or progress difficult
(v.) 1. to create difficulty for the work or activity of
2. to prevent passage through by filling with something
(syn.) balk, bar, deterrent, fetter, hurdle, imped