There are three basic ways of _____ language to writing, and all known graphic systems use one or a combination of these.
| A．committing | B．attaching | C．comparing | D．relating |
It _______ nearly two weeks ________ I had received his letter.
| A．is, that | B．was, that | C．is since | D．was, since |
----This returned Chinese scholar has become one of the top experts in this field.
----Yes,I know him very well.He_________in Africa with animals for eight years.
| A．has worked | B．had worked | C．worked | D．has been working |
----Does Liu Hua serve in the army?
----No,but he__________in the army for three years.
| A．served | B．has served | C．is serving | D．would serve |
The boss praised the young man for his hard work, though he ____ experience.
| A．was lack of | B．was lacking in | C．lacks of | D．was lacking of |
._____ in thought , he almost ran into the car in front of him .
| A．Losing | B．Having lost | C．Lost | D．To lost |