If you don’t understand, don’t hesitate27/80Mark the letter A, B,C or D on your answer sheet that completes each of the following questions or that is closest in meaning to the underlined part If you don’t understand, don’t hesitate________.ask a questionto ask a questionasking a questionto askin a questionGiải thíchĐáp án là B. hesitate + to V: lưỡng lự, do dự ....