Đáp án:
Lời giải:
CaO+2H2O=>Ca(OH)2 +H2
Nhận biết hcl naoh back2 na2so4 k dùng quỳ tím
Giải hệ phương trình {x+3y=4
{2x+5y=7
Giải phương trình x mũ 2 - 5x + 3 = 0
Choose the best answer.
I think you should buy _____ pack of mineral water instead. And you can also buy _____ snacks such as potato crisps, 3 kilos of mandarins, 2 kilos of apples, 3 bunches of bananas, ______ cookies and soft candies.
We should decorate our living room with _____ orange banner. We also need ________ ribbons, balloons, party hats and costume.
I think that ______ cauliflower is not enough for 3 people. Let’s buy one more.