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The Bank of China, having so far woven its network in 27 countries, ______ its business in Brazil in June 2009.
| A．has started | B．was starting | C．will start | D．started |
That was the first time I ______ there and I was impressed by the friendly people very much.
| A．go | B．was going | C．had gone | D．have gone |
Smoking too much may ______ lung cancer and cause other diseases.
| A．devote to | B．attend to |
| C．contribute to | D．come to |
Mary felt sad over the loss of photos she had shot in Australia, ______ that was a memory she especially treasured.
| A．as | B．which | C．when | D．where |
With the guide ______ the way, we finally got to the village which we were looking for.
| A．led | B．leading | C．to lead | D．had led |
Perseverance is a kind of quality, and that is ______ it takes to do everything well.
| A．why | B．that | C．what | D．which |