【简答题】车削加工中,切削用量三要素是指__________ 、__________ 和__________。
【单选题】Ever since John Burrows and his wife Carol opened their first hair salon in 1983, they have been taking on apprentices. 'In my generation, an apprenticeship was the way to learn a trade so it was the ...
A.
is the only way to begin a career in his generation.
B.
can help him find the qualified staff he wanted.
C.
is the most important factor to the company's success.
D.
secures his business to confront no problems all along.
【单选题】用8051的定时器T0定时,用方式2,则应( )。
A.
启动T0之前首先向TH0置初值,TL0置0,以后每次计数结束时要重新给计数器重新置初值
B.
启动T0之前首先向TH0、TL0置初值,以后每次计数结束时要重新给计数器重新置初值
C.
启动T0之前首先向TH0、TL0置0,以后不在置初值
D.
启动T0之前首先向TH0、TL0置相同的初值,以后不在置初值
【简答题】车削加工中,切削用量三要素是指 _______ 、______和_______,它们的单位分别是mm、m /min和mm/r。
【单选题】用8051的定时器T0作定时方式,用模式2,则工作方式控制字为 。
【多选题】用 8051 的定时器 T1 作定时方式,用模式 2 ,则初始化编程为 。
D.
置 TH0 、 TL0 相同初值,以后不须重新置数
E.
置 TH0 、 TL0 相同初值,以后须重新置数
【单选题】用8051的定时器T0定时,用方式2,则应( )。
A.
启动T0前向TH0置入计数初值,TL0置0,以后每次重新计数前要重新置入计数初值
B.
启动T0前向TH0、TL0置入计数初值,以后每次重新计数前要重新置入计数初值
C.
启动T0前向TH0、TL0置入不同的计数初值,以后不再置入
D.
启动T0前向TH0、TL0置入相同的计数初值,以后不再置入
【单选题】用at89c8051的定时器T1作定时方式,用模式2,则工作方式控制字为( )
【单选题】用8051的定时器T0定时,用方式2,则应()
A.
启动T0前向TH0置入计数初值,TL0置0,以后每次重新计数前要重新置入计数初值
B.
启动T0前向TH0、TL0置入计数初值,以后每次重新计数前要重新置入计数初值
C.
启动T0前向TH0、TL0置入计数初值,以后不再置入
D.
启动T0前向TH0、TL0置入相同的计数初值,以后不再置