Generally speaking, there are four essential factors _______ Chinese cooking is usually judged, namely, color, shape, smell and taste.
I thought it a pity __________ him to the tea party.
.A reward of 1,000 dollars will be given ________ can find the lost child.
.So often ______ in recent years that it has almost become a rule.
.The farmer who admitted ______ the tiger was severely punished.
.They ______ be at home. You see, the door is locked from the outside.