9.下列各式属于最简二次根式的是( )
| A. | $\sqrt{18}$ | B. | -$\frac{1}{2}\sqrt{3}$ | C. | $\frac{1}{\sqrt{2}}$ | D. | $\sqrt{\frac{1}{5}}$ |
8.在20,-$\frac{1}{2}$$\sqrt{3}$,-$\sqrt{8}$,$\root{3}{27}$,0.101001,…2π,-$\frac{22}{7}$中,无理数的个数是( )
| A. | 2 | B. | 3 | C. | 4 | D. | 5 |
7.$\sqrt{16}$的算术平方根是( )
| A. | 2 | B. | 4 | C. | ±2 | D. | ±4 |
4.
小敏不慎将一块平行四边形玻璃打碎成如图的四块,为了能在商店配到一块与原来相同的平行四边形玻璃,他带了两块碎玻璃,其编号应该是( )
0 284242 284250 284256 284260 284266 284268 284272 284278 284280 284286 284292 284296 284298 284302 284308 284310 284316 284320 284322 284326 284328 284332 284334 284336 284337 284338 284340 284341 284342 284344 284346 284350 284352 284356 284358 284362 284368 284370 284376 284380 284382 284386 284392 284398 284400 284406 284410 284412 284418 284422 284428 284436 366461
| A. | ①,② | B. | ①,④ | C. | ③,④ | D. | ②,③ |