<p><strong>Câu 17.</strong> English has become a second language in countries like India, Nigeria or Singapore where _________ for administration, broadcasting and education.</p>
<p><strong>Câu 18.</strong> The telephones_________ by Alexander Graham Bell.</p>
<p><strong>Câu 19. </strong>Lots of houses_________ by the earthquake.</p>
<p><strong>Câu 20. </strong>Gold_________ in California in the 19th century.</p>