1.The frightening scene frightened the boy. He felt frightened but he tried to hide his fright．(fright)
2.①(2019·北京西城区高一期末)Knowing your strengths(strong) and weaknesses will help you achieve your dreams.
②And the best way to__strengthen(strong) willpower is to make it into a habit.
③Having failed once again, he didn’t have the strength to__have(have) another try.
3.①As we all know, parents focus their attention on their children’s study, because it is concerned with/in their future.
②Concerned(concern) about the health of her son, Mrs. Jackson went to the school to visit him every week.
③I am writing to see if it is possible for you to provide me with information concerning(concern) the way of learning English.
④__As__far__as__I’m__concerned(就我而言)，riding bicycles is a good solution to air pollution.
