Unable to open 为什么要加个 to ,to代表什意思?

Unable to open Unable to open 为什么要加个 to ,to代表什意思? unable to open file是什么意思 unable to exit while consoles are open genesis2000出现unable to open directory Unable to open hyperlink;The specified file was not 请问：the oceans were open to sail中open为什么不加ing? Unable to he was unable to open the door.这个句子to open the door是什么成分?unable是表语,那后面的呢? 电脑出现unable to open hyperlink:this specifile was not found怎么解决 C++Builder [linker Error]Unable to open UNIT1.怎样解决啊,新手,求谅解 He's still unable to make himself____in English.为什么要填understood而不是understand? Is the shop open,要加ing吗为什么 when is the bank open?it is open in 8am其中open前为什么要加is.还是应回答it open in 8am 省掉is i could hardly open it为什么不在could与hardly中加to应该是在hardly与open中加to Unable to write to unable to connect to unable to 我手机在安装UC浏览器时会出现unable to install,要怎么处理?