13. --Hi, Lydia. Are you going to the concert on Friday? - -I’d like to. But there are so many problems ____.
Towards evening, the patient opened his mouth as if _____ something to his son.
“Well, I’ll tell you a secret ...” said the boy, with his mouth almost _____ my ear.
They looked forward with hope _____ a chance to receive further education.
I regret _____ hard at school, or I would have succeeded in passing the exam.
. We should prevent such a silly mistake _____ again.