Only when it is hungry ______ a human being.
| A．a lion will attack | B．a lion should attack |
| C．will a lion attack | D．should a lion attack |
I love to buy a new dress at a _______ at the Spring Festival．
| A．discount | B．bargain | C．pay | D．cost |
—How long has this bookstore been in business?
—_______ 1996．
| A．After | B．In | C．From | D．Since |
— Would you mind helping me with my suitcase? I really can’t manage it by myself．
—________．
| A．My pleasure | B．No problem |
| C．Not at all | D．Never mind |
______ after a long walk, Henry called and said he couldn’t come．
| A．Having worn out | B．Being worn out |
| C．To wear out | D．Worn out |
At the age of six, my son _____ ask me a lot of strange questions, and some of them were too hard to answer．
| A．would | B．should | C．must | D．might |