–How do you keep in touch with your old classmates or schoolmates? -- By chatting with them on the Internet, _______for three hours every day.
They began to consider what use could ___ the natural resources(资源).
____ number of students in our class ____ larger than that in theirs.
He refused to ___ to the terrible weather only at the last moment because he had no choice.
It’s known to all that life’s ____ is full of hardships.
I _______ Beijing in a few days. Do you know when the earliest plane ________?