They ________ the train until it disappeared in the distance.
---How many eggs are still there in the fridge, Bill? --_____.
About ___ of the teahers is our school ___ young people under thirty.
___Mr. Chen is waiting outside to speak to you. He appears to be quite ___ important person.
Suan! Where have you been? You have no idea ___ worried I was !
___ my opinion, Americans eat too much meat.