— Have you found your English book? — I am not sure ____ I could have left it.
When I talked about the thing,I felt Jane watching me uncomfortably,looking________ she wished to speak.
In most western countries on April Fool’s Day,people often play________ trick on each other;children especially have great________ fun.
—Thank you very much for helping me out of trouble,Bob.—________.
“ Will you repeat the question?” “ Certainly. It’s certain that you _____ attention.”
“ Will you repeat the question?”
“ Certainly. It’s certain that you _____ attention.”
_____ you’ve a chance, you might as well make full use of it.