4.正六边形的周长为12,则该正六边形的内切圆的半径为( )
| A. | 1 | B. | $\sqrt{3}$ | C. | 2 | D. | 3 |
3.据天津市统计局统计,2014年国庆黄金周七天长假,全市共接待游客755.52万人次,将755.52万用科学记数法表示应为( )人次.
| A. | 7.5552×102 | B. | 7.5552×103 | C. | 7.5552×106 | D. | 7.5552×107 |
17.
如图是一次函数y1=ax+b,y2=cx+d的图象,可以得出不等式组$\left\{\begin{array}{l}{ax+b>0}\\{cx+d<0}\end{array}\right.$解集是( )
0 282298 282306 282312 282316 282322 282324 282328 282334 282336 282342 282348 282352 282354 282358 282364 282366 282372 282376 282378 282382 282384 282388 282390 282392 282393 282394 282396 282397 282398 282400 282402 282406 282408 282412 282414 282418 282424 282426 282432 282436 282438 282442 282448 282454 282456 282462 282466 282468 282474 282478 282484 282492 366461
| A. | x<-2 | B. | -2<x<1 | C. | x>0 | D. | x>1 |