f.3 eng simple present

When the sun sets, it moves down in the sky and disappears. (日落) Set is an intransitive verb in this case.It doesn’t have an object. You can’t put it into passive voice. When set is usedas an adjective, it does not mean 日落. You also can’t use presentcontinuous tense. You use present simpletense to state the fact. The sun is not set in the east. (~ passive voice) WRONGThe sun doesn’t set in the east. RIGHT

2012-01-09 21:09:56 補充：
Correction:

used as (not usedas),
present continuous (not presentcontinuous)
simple tense (not simpletense)