—Please let me know where David is. I couldn’t find him anywhere.—Well, he _____have gone far—his coat’s still here.
John didn’t feel well yesterday; otherwise he ______ to see his friend off at the airport.
_____ you are familiar with the author’s ideas, try reading all the sections as quickly as you possibly can.
Before the first nonstop flight made in 1949, it_____ necessary for all planes to land for refueling.
Students who pass the test will be ______ to the next grade, as has been announced.
When choosing a product, I sometimes try to figure out the meaning___ to its brand name.