下图是中国同盟会广西支部在20世纪初某一期报刊上的插图，其含义是

①推翻帝国主义在华统治②革命前途光明，曙光就在前面

③资产阶级共和国已经建立④推翻满清，解除民族压迫

A．①③

B．②③

C．②④

D．①④

The UNIX operating system is made up of three parts; the kernel, the shell and the programs. The kernel of UNIX is the (71) of the operating system: it allocates time and memory to programs and handles the filestore and communications in response to (72) .
The shell acts as an (73) between the user and the kernel. When a user logs in, the (74) program checks the username and password, and then starts another program called the shell. The shell is a command line (75) (CLI). It interprets the commands the user types in and arranges for them to be carded out. The commands are themselves programs: when they terminate, the shell gives the user another prompt (% on our systems).

A．interface

B．interconnect

C．changer

D．boundary