It’s beyond our comprehension that Jim, who tops the class in English, ________ have difficulty translating such a simple sentence.

–Do you think we are going the right way to the Forbidden City? —Sorry, I’m not sure．But it _______ be．

Mr. Bush is on time for everything. How ____ it be that he was late for the important meeting?

—Did you visit the museum last week? —No, we _____, but we spent too much time shopping.

 You ______be tired after working for eight hours without ______ a rest.