______ their service, the workers of the hotel are active in learning English.
| A．Improving | B．To improve |
| C．Improve | D．Having improved |
As is well known, the brain performs a very important _______, which controls the nerve system of the body.
| A．motion | B．action | C．function | D．fact |
_____ is a good form of exercise for both young and old.
| A．Walk | B．Walking |
| C．The walk | D．To walk |
“May I take your order now?” “We’d like three black _______ and two green _______.”
| A．coffee, cups of teas | B．coffees, teas |
| C．cups of coffee, tea | D．cup of coffees, teas |
She raised her finger to her lips as _____ for silence.
| A．an idea | B．a mark |
| C．a sign | D．a word |
Jim is ______ person, and everyone is willing to be ______ with him.
| A．so kind a, friends | B．so a kind, friends |
| C．so kind a, friend | D．so a kind, friend |