利用_______网可以确定地球表面任何一个地点的准确位置。
经纬
Dr. Frank failed many times but he finally _________ to find a successful way to solve the problem.
A．broke through
B．put up
C．picked out
D．gave away
执行语句for(i=1;i++＜4;);后变量i的值是______。
A．3
B．4
C．5
D．不定
