As is reported, it will be more than 20 years ________ humans are able to walk on Mars.
It’s quite warm _____ January.
The key _____ four modernizations lies _____ the science and education.
What one thinks and feels is mainly _____ traditions, habits and education.
Get in touch with them, for they will be anxious _____ news of your arrival.
I like the climate here _____ the wind blows .