Bats are surprisingly long-lived creatures, some ___ a life span of around 20 years.
| A．have | B．had | C．having | D．to have |
—Can you keep an eye on my bag, Mary? I just want to use the bathroom.
—___________. It will be safe with me.
| A．I don’t think so | B．Forget it | C．Go ahead | D．You’re welcome |
The poor man’s life was _________ the king.
| A．at the mercy of | B．at the call | C．at the service | D．at the experience |
Jumping out of ______ airplane at ten thousand feet is quite _______ exciting experience.
| A．/; / | B．/; an | C．an; an | D．the; the |
The company was named Gates Hall ______ a man named James Gates.
| A．in need of | B．in search of | C．with the help of | D．in memory of |
--- Where is Jack? I can’t find him anywhere.
--- He ______ his homework upstairs.
| A．might have done | B．must have done | C．might be doing | D．must do |