______ there are living creatures in the outer space as those on Earth hasn’t been proved so far.

Some students think they enjoy reading just out of interest, but others argue that a better score is their main ________.

 Since the early nineties, the trend in most businesses has been toward on-demand, always-available products and services that suit the customer’s ________ rather than the company’s.

 The head office of the bank is in Beijing, but it has _______ all over the country.

To learn English well, we should find opportunities to hear English______ as much as we can.