be open,当主语是三单时,open加s吗?如：The shopping mall is open at 9 o’c

be open,当主语是三单时,open加s吗?如：The shopping mall is open at 9 o’c The shopping mall is open from 8 p.m.to 9 p.m.对from 8 p.m.to Let's open the door!的主语 The library is open at 9 o'clock.对“at 9 o'clock提问” it's 8:15.the mall will open at 10:00(同一句转换) look,the door is open,为什么open不加ing? The shop is open at seven open The mall is open from 9:00 to 10:00.用how long 对吗 be open Is the shop open,要加ing吗 The shop________ at eight o'clock every day.A.is open B.is o