He _______ have completed his work；otherwise, he wouldn’t be enjoying himself by the seaside.

We were looking for you all this morning. You    office without a word.

—Do you know whose dictionary it is?—It ________ be Ann’s. Look! Her name is on the first page.

— _ I use your eraser, Rose?— Sure. Here you are.

As a well-known Chinese saying goes, “If you want to be rich, you______ first build roads.”