5.若$\sqrt{x+y-1}$+(y+2)2=0,则x-y的值为( )
| A. | -5 | B. | -1 | C. | 1 | D. | 5 |
4.
如图,若a∥b,∠1=60°,则∠2的度数为( )
0 297182 297190 297196 297200 297206 297208 297212 297218 297220 297226 297232 297236 297238 297242 297248 297250 297256 297260 297262 297266 297268 297272 297274 297276 297277 297278 297280 297281 297282 297284 297286 297290 297292 297296 297298 297302 297308 297310 297316 297320 297322 297326 297332 297338 297340 297346 297350 297352 297358 297362 297368 297376 366461
| A. | 40° | B. | 60° | C. | 120° | D. | 150° |