clock() 和 time()我是c++新手,请问这两个函数分别用在哪?两者的返回值各代表什么?time（）好像还有个参数,那个参数干什么用的?

clock time time库中的time()和clock()有什么区别?RT clock() 和 time()我是c++新手,请问这两个函数分别用在哪?两者的返回值各代表什么?time（）好像还有个参数,那个参数干什么用的? --What's the time ---It's ____ eight o'clock .A.at B.on C.in D.around 到底选什么?希望得到有力的解释和理由! What time is it now?A.It'eleven two o' clock.B.A.It's eleven two o' clock.B.It's two eleven o' clock.C.It's twelve o' clock.D.It's eleven twelve o' clock.急 It is five o'clock.It's time ______ go home.( )It is five o'clock.It's time ______ go home.A.for B.to C.of What's the time?It's___6 o'clock.A.at B.for C.of D.about Its 12o'clock It's time ______lunch A,have B,has C,to have That's the time ( )the clock.A.on B.in C.under the train arrived on time at 5 o'clock 这么说对不对on time 和at 5 o'clock是否有问题如果有问题, it clock it is time for造句 what time?----At four o' clock. () time is it now? () 4 o'clock It's seven o'clock in the evening.It'time()dinner.A.in B.for C.at请说明为什么 it's nine o'clock.it's time bed（填空）A.for B.to C.for go to a:what time is the party?b:It_______at two o'clock. A.start B.starts C.started _______did you go to bed last night?At nine o'clock.A.What time B.What C.How D.Who o'clock和clock的中文意思