What does the word “it” in the first sentences refer to?

Mark the letter A, B, C or D on your answer sheet to choose the word whose underlined part is pronounced differently from the rest.

Choose the word that has the underlined part pronounced differently from the others.

Choose the word whose stress is placed differently from that of the others.

Choose the word whose stress is put differently from that of the others.

Choose the word whose stress is put differently from that of 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 best option to complete the following sentences.

In the age of technology, you can _______ advantage of new applications which are very useful for learning English.