Helen was much kinder to her youngest son than to the others , ____ , of course , made the others envy him .
| A．who | B．that | C．what | D．which |
Our research has focused on a drug which is so _____ as to be able to change brain chemistry.
| A．powerful | B．influential | C．monstrous | D．vigorous |
The boy slipped out of the room and headed for the swimming pool without his parents' _____.
| A．command | B．conviction | C．consent | D．compromise |
In this factory, suggestions often have to wait for months before they are fully _____.
| A．admitted | B．acknowledged | C．absorbed | D．considered |
. Jim isn't _____, but he did badly in the final exams last semester.
| A．gloomy | B．dull | C．awkward | D．tedious |
. The manager said that they had an _____ plan if the plan they had submitted was not accepted.
| A．alternate | B．alternative | C．absolute | D．appreciable |