According to the passage, what kind of signal has long periods of light that are regularly broken by two or more periods of darkness?

Choose the word whose underlined part is differently from the others

Choose the word which has the underlined part pronounced differently from the rest.

Choose the word whose underlined part is pronounced differently from others.

Choose the word that has the stress different from that of the other words.

Choose the word which has a different stress pattern from the others.

Choose the best answer to complete the sentence.

Parents must ______ a good example for their children.

Choose the best answer to complete the sentence.

Community service often includes ___________ activities which help students to develop better.