小男孩调皮地咧嘴一笑，眼中闪烁着狡黠的光芒。

The young boy grinned ___mischievously, a ___twinkle in his eye.

圣诞树上的小彩灯在黑暗中闪闪发光。

The little lights on the Christmas tree ___twinkle in the dark.