21. the boy sat there sad, _______ by his friends. a. feeling betrayed b. to be betrayed c. been betrayed d. having betrayed 22.the girl is _______ to give us some help if asked. a. possible b. likely c. probably d. possibly 23.the people are ______ about the newly-made discoveries ______ the change of people’s way of life in the future. a. concerned; concerned b. concerning; concerning c. concerning; concerned d. concerned; concerning