—Why didn’t you keep your words，Billy?
—Sorry, dear. But I really forgot where I was ________ to meet you.
| A．demanded | B．imagined | C．supposed | D．guessed |
When it ______ research into heart disease and its effects on the body, we do not have adequate substitutes for the use of animals.
| A．refers to | B．related to | C．comes to | D．talks to |
Would it be ___ for you to pick me up at four o’clock and take me to the airport?
| A．free | B．vacant | C．handy | D．convenient |
—You speak very good French!
—Thanks. I ______ French in Sichuan University for four years.
| A．studied | B．study | C．was studying | D．had studied |
We should consider _______ use can be made of such a piece of cloth.
| A．what | B．that | C．how | D．which |
—He got his first book published. It turned out to be a bestseller.
—When was ________?
—______ was in 2000 when he was still in college.
| A．that; This | B．this; It | C．it; This | D．that; It |