下列体现中 * * 伟大民族精神的有[     ]

①富贵不能淫，贫贱不能移，威武不能屈

②万般皆下品，惟有读书高

③天行健，君子以自强不息

④‘特别能吃苦、特别能战斗、特别能攻关、特别能奉献“的载人航天精神

A．①③④

B．①②④

C．①②③

D．②③④

Inside the computer, the operation system (of another software module called a data communication (71) )must decide which program will get control next. Each program remember, is associated (72) . a particular front -end port. If a program’s data have not yet reached its front - end buffer, there is no point giving that program control. Thus the data communication monitor sends its own (73) signal to the front -end devices next port is polled. Note that the (74) computer speed. The computer never has to wait for a terminal or a communication line. Instead, it is the expressive front - end processor that waits for the slower system (75) to respond.

（74）处填（）。

A.great

B.huge

C.mainframe

D.large