A foreign language like English is difficult to learn, so you ____________ work too hard.

He is not native; if he were, we ______ this discussion over his identity.

It is strange that the small boy _________ work out such a difficult exercise, which is even hard to settle for adults.

I＿＿＿＿＿＿often go fishing when I lived in the countryside. 

Flowers suddenly burst out everywhere on the same day every spring, as if they       in tune with one another.