Choose the best option to complete the following sentences.

To ___________ is to keep and protect something from damage, change or waste.

Choose the word whose underlined part is pronounced differently.

Find the word whose main stress is different from the others.

Choose the best option to complete the following sentences.

Since the appearance of electronic devices, lessons have become more and more _____ and effective.

Choose the word whose underlined part is pronounced differently.

Find the word whose main stress is different from the others.

Choose the best option to complete the following sentences.

Do you think there would be less conflict in the world if all people __________ the same language?

Choose the best option to complete the following sentences.

_________ will lead to the extinction of rare animals due to the loss of their habitats, and extreme floods and land erosion.