—Have you seen my dictionary? ---- Is it _______ you bought last week? Perhaps _______ is on your bed.

I hate ___ when the weather in Changsha becomes freezing cold because there is no heater inside. 

The Science Museurn，   we visited during a recent trip to Britain，is one of London’s tourist attractions．

--How many eggs are still there in the fridge, Bill? ---_____.

One of the most important questions they had to consider was _________ of public health.