Many people believe that hunger is only a problem in the developing world. ______, it is a problem all over the world.
To get a better grade, you should ______ the notes again before the test.
Sometimes proper answers are not far to seek ______ food safety problems.
In that school, English is compulsory for all students, but French and Russian are ______.
Would you like tea or coffee? --_____, thank you. I’ve just had some water.
We can never expect ____ bluer sky unless we create _____less polluted world.