—You've dropped ________ “s” in the word “acros”.—Oh, ________ letter “s” should be doubled like this “across”.
A stranger ___ his room without his permission.
Let’s congratulate you ___ your success in every aspect of life and drink ___ it.
Suddenly I met a friend of ___ and we said hello to each other .
The concert he played sounded ___.
Where’s he? He ___ on the phone.