S = 1 - 2 - 3 + 4 +... + 2021 - 2022 - 2023 + 2024 + 2025

   = (1 - 2 - 3 + 4) +... (2021 - 2022 - 2023 + 2024) + 2025

   = 0 + 0 +... + 0 + 2025

   = 2025

1, Which is (cold) the coldest place in Viet nam?

2, Kien (play) is playing chess at the moment.

3, He (get) gets to work by bike everyday, but today he (go) is going to work by bus.

4, Our house is small, we want a (big) bigger house.

5, Trung (want) wants (become) to become a musician. He (think) thinks it is (good) the best choice.

6, The Amazon River (wide) is the widest River in the world.

7, Listen!Our teacher (speak) is speaking.

8, Minh (cycle) cycles to school everyday.

9, Mrs Hoa (not teach) doesn't teach English. She (teach) teaches Maths.

10, What is he (do) doing in his room?

Số số hạng là:

    (98 - 2) : 2 + 1 = 49 (số hạng)

Tổng dãy số trên là:

Số số hạng là:

   [100 - (- 1)] : 1 + 1 = 102 (số hạng)

Tổng là:

   {[(- 1) + 100].102} : 2 = 5049

                       Đáp số: 5049

1. People play it very loud on ... guitars. It's so noisy.
A. electricity       B. electric          C. electricial      D. electrician

2. It's very ... to eat fried food every day. You can become overweight.

A. healthy          B. unhealthy     C. health            D. healthily 

  Every summer, Vietnamese secondary school students have the chance to participate in a campaign (1) __________  Hoa Phuong Do (The Red Flamboyant). This campaign aims at helping (2) __________ fortunate people in the societies. Students can take part in many activities. For example, they can organize summer activities for children, teach children (3) __________  to swim or provide review lessons. These activities help students contribute (4) __________   the community and (5) __________  into helpful citizens in the future.

1. A. called       B. calling   C. call

2. A.less          B.lots of      C. much

3. A.what         B.how         C.why

4. A.in              B.with          C. to

5. A.become  B. develop    C. grow

 Thì TLĐ diễn tả một hành động sẽ xảy ra trong tương lai

Eg: I will go to cinema next month.

 Thì HTTD diễn tả hành động mang tính quyết định nhanh

Eg: We are playing soccer at the moment.

48/120 = 2/5

-60/108 = -5/9

Số số hạng là:

      (99 -1) : 2 + 1 = 49 (số hạng)

Tổng các số hạng là:

      (99 + 1)×49 : 2 = 2450 

                        Đáp số: 2450

5(x + 11) = - 75

   x + 11  = (- 75) : 5

   x + 11  = - 15

   x          = - 26

 Vậy x     = - 26