______ we know, the air quality in the city has improved over the past two years.
Passed from father to son, the music has not changed for eight centuries,and among the richer Naxi people, ________ knowledge of this music showed that you were ________real gentleman.
Sometimes I’m dying ______ him about it.
Wherever such an area is located, it will be immediately ______ by the enemy if armed forces are lacking.
His hard work paid______ when he got the result.
While typing, Helen has a habit of stopping ______ to give her long and flowing hair a smooth.