ủa thí google để lèm gì

google đẻ làm  gì

1 mustn't

2 has to

3 have to

4 don't have to

5 has to

         1.            Hoàn thành các câu dưới đây với thể khẳng định hoặc phủ định của “must”, “have to”, “has to”.

              1.1.        Students………mustn't……...look at their notes while they are taking the exam.

              1.2.        My mother has a terrible headache so she………… has to…...stop working today.

              1.3.        There is an accident and the traffic is blocked. We………… have to…...to stay here for a while.

              1.4.        You………don't have to……...do that, Mary. I'll do it later.

              1.5.        He…………must…...wait in line like anyone else.

People will have clean environment if we have the ability to stop making it polluted.

\(a,=2\sqrt{2a}+3\sqrt{2a}-4\sqrt{2a}=\sqrt{2a}\\ b,=3\sqrt{5}-3+\sqrt{5}=4\sqrt{5}-3\\ c,=\dfrac{\sqrt{3}-1+\sqrt{3}+1}{\left(\sqrt{3}+1\right)\left(\sqrt{3}-1\right)}=\dfrac{2\sqrt{3}}{2}=\sqrt{3}\\ d,=-7+5-2\cdot\dfrac{2}{3}+\dfrac{1}{3}\cdot3=-2-\dfrac{4}{3}+1=-\dfrac{7}{3}\)

Children must / have to start school when they are five.