Jim is old enough to look after the pet dog ______.
The professor could hardly find sufficient grounds _____his arguments in favor of the new theory.
A survey was carried out on the death rate of those who were infected by SARS, ________were surprising.
In recent years much more emphasis has been put______ developing the students productive skills.
_____ of water makes Death Valley a desert, but it is by no means devoid.
No matter how frequently _____ the works of Beethoven always attract a large number of people.