Will you go with us for an outing on Saturday?— I’d like to, but I am really busy these days. I can’t _______ a whole weekend.

The young men walked _____ the forest and came to a big river at last. [ ]

I will send you an e-mail as soon as I ______ in Canada. 　　[ ]

My teacher said to me with a smile, “Well, you ________ to worry about your lessons.”

There are ________ days in a year.