A:not until midnight did he go
B:until midnight that he didn’t go
C:not until midnight that he went
D:until midnight when he didn’t go
某物质能与水反应,将少量该物质加到饱和石灰水中,石灰水变浑浊,则下列说法正确的是
本世纪头20年的奋斗目标是( )