21£®—My dog's really fat.
—You ________ have given her so much food.
A£®wouldn't¡¡¡¡¡¡¡¡¡¡¡¡¡¡B£®can't C£®shouldn't D£®mustn't
22£®—The head teacher said we had only three days to finish the project.
—Don't worry. We have already ________ two thirds of it.
A£®taken over B£®got through C£®made up D£®given away
23£®Only when we saw the photos about the air crash ________ how terrible it was.
A£®had we known B£®we had known
C£®did we know D£®we knew
24£®If any of these symptoms ________ while you are taking the medicine, consult your doctor immediately.
A£®knocks B£®occurs C£®reaches D£®applies
25£®________ the pressure increased day by day, students devoted themselves to their study not to let their parents down.
A£®When B£®Where C£®Before D£®Although