1 . The most universal ________ expression is the smile—its ________ is to show happiness and put people ________ ________.（根据课文完成句子）

2 . No one was ever ________ watching him—his subtle acting made everything ________.（根据课文完成句子）

3 . You may find it ________ that Charlie was taught to sing as soon as he could speak.（根据课文完成句子）