• 1. (2019七上·乐昌期中) ①-5+6=②-7×（-5）=③（-8）+17=④2÷（ ）=

  ⑤-3.45×9.98×0=⑥-2b+(+3b)=⑦-1³×3=

  ⑧4ab-(-4ab)=⑨5+5÷(-5)=⑩3-(-1)²=