Rút gọn biểu thức sau (giả thiết các biểu thức chữ đều có nghĩa):$\frac{2+\sqrt{2}}{1+\sqrt{2}};\frac{\sqrt{15}-\sqrt{5}}{1-\sqrt{3}};\frac{2\sqrt{3}-\sqrt{6}}{\sqrt{8}-2};\frac{a-\sqrt{a}}{1-\sqrt{a}};\frac{p-2\sqrt{p}}{\sqrt{p}-2}$

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.

Choose the best answer.

We should decorate our living room with _____ orange banner. We also need ________  ribbons, balloons, party hats and costume.

Choose the best answer.

I think that ______ cauliflower is not enough for 3 people. Let’s buy one more.