If we going on throwing trash, the environment will be polluted.

We stayed at home_______ it snowed heavily.

Remember to_______ off the TV when there is noone in the room.

Choose the word that has underlined part pronounced different from the others:

What is NOT mentioned as an advantage of solar cells?

Choose the best option by cirling A, B, C or D to complete the following sentences.

My sister is going to_______ my children when I'm at work

What does the word "they" in line 5 refer to?

Read the text and choose the best answer to the following questions by circling A, B, C or D.

Solar energy is a long lasting source of energy which can be used almost anywhere. To generate solar energy, we only need solar panels and the sun! Solar panels can easily be installed on house roofs, so no new space is needed and each user can quietly generate their own energy. Compared to other renewable sources, they also possess many advantages. Wind and water power rely on turbines which are noisy, expensive and easy to break down. Solar panels are totally silent and non-polluting. As they have no moving parts, they require little maintenance and have a long lifetime.

However, solar energy also has some disadvantages. We can only generate solar energy during daytime because the system depends on sunlight. Besides, solar panels require large area to work effectively. The main disadvantage of solar energy is that it costs about twice as much as traditional sources such as coal, oil, and gas. This is because solar panels are expensive. 

What does the word "advantages" in line 16 mean?

We are_______ in environmental problems. (INTEREST)

Choose one of the mistake in each sentence.

 I suggest we should helping elderly people and war invalids with their housework.

Which of the following is NOT a traditional source of energy?

You will_______ the test , if you don't study hard.

Water_______ is a big problem in modern life. (POLLUTE)             

We suggest_______ energy- saving bulbs instead of ordinary 100- watt bulbs.