It was very rude of her to leave without telling us.
You never know how much difficulty we had ___the problem.Luckily, we managed to solve it with his help.
I‘m not sure _________ next week.
Nancy doesn’t want to buy the skirt because ______ the colour ______ the size fits her.
—As a teacher, we can’t be _______ patient with our students.
It’s believed that our moods are sometimes _______ by colours.Many scientists are doing research on this subject.