The heat in the desert is__________; therefore there are few plants growing there.

— The weather isn’t good enough for an outing , is it？— No. We can’t have _________at this time of the year.

As there is less and less coal and oil, scientists are exploring new ways of making use  of ______________   energy, such as sunlight, wind and water for power and fuel.

There is a ______ cup on the table.

ORBIS doctors     many patients, but patients do not have money to pay for the     .