Modern science has given ____clear evidence ____ smoking can lead to many diseases ____ it’s time for us to take measures.
Tom failed ______ the experiment yesterday.
The world is _______ seven continents and four oceans.
Japan is an ______ industrial country.
What way are you thinking of _______ rid of this kind of pollution?
---Who were those people with the banner? ---A group ______ itself the League for Peace.