our workshop ________since two years age a.was open b.opened
our workshop ________since two years age a.was open b.opened c has been open d.has opened
a since不是与完成时连用吗,这里为什么选a was open中 open是形容词吗?难道这样表示 be open 就是延续性的了?如果c 改为 has been opened 能对呢?但是好像open 始终性动词吧.