，在括号中填上线与线的位置关系．a∥b，a⊥c．
18．口算题
0 158419 158427 158433 158437 158443 158445 158449 158455 158457 158463 158469 158473 158475 158479 158485 158487 158493 158497 158499 158503 158505 158509 158511 158513 158514 158515 158517 158518 158519 158521 158523 158527 158529 158533 158535 158539 158545 158547 158553 158557 158559 158563 158569 158575 158577 158583 158587 158589 158595 158599 158605 158613 199269
| 0.82+0.08= | 73×1= | 0.63×10= | 4÷10= |
| 17÷1000= | 0.56+0.4= | 1.25×100= | 5.6+99= |
| 100÷25= | 1-0.93= | 90-0.9= | 1.89÷100= |
