单项选择题
Just as a book is often judged ______ by the quality and appearance of its cover, a person is judged immediately by his appearance.
单项选择题 Walking is believed to be one of the best ways for a person to ______ healthy.
单项选择题 He has achieved ______ success during the past ten years.
单项选择题 The scientist has made quite a few discoveries, ______ of great importance to the whole world.
