She reached the top of the hill and stopped _____on a big rock by the side of the path.
________ energy is generated from natural resources—such as sunlight, wind, rain, tides and so on.
Effective measures have been taken to prevent _______pollution.
-- I’m thinking of the test tomorrow. I’m afraid I can’t pass this time.-- ______! I’m sure you’ll make it.
After that, he knew he could ________any emergency by doing what he could to the best of his ability.
For him_____ stage is just _____ means of making a living.