10.下列命题中,假命题是( )
| A. | 等弧所对的圆周角相等 | |
| B. | 经过圆心的每一条直线都是圆的对称轴 | |
| C. | 直径所对的圆周角是直角 | |
| D. | 平分弦的直径垂直于弦,并平分弦所对的弧 |
9.如果2是方程c-x2=0的一个根,那么常数c是( )
| A. | 2 | B. | -2 | C. | 4 | D. | -4 |
8.在下列图案中,既是中心对称,又是轴对称图形的是( )
0 294297 294305 294311 294315 294321 294323 294327 294333 294335 294341 294347 294351 294353 294357 294363 294365 294371 294375 294377 294381 294383 294387 294389 294391 294392 294393 294395 294396 294397 294399 294401 294405 294407 294411 294413 294417 294423 294425 294431 294435 294437 294441 294447 294453 294455 294461 294465 294467 294473 294477 294483 294491 366461
| A. | B. | C. | D. |