South Korean rapper PSY’s hit song Gangnam Style made history on December 20 as first-ever video on youtube. com to reach 1 billion views.
She pretended _______ me when I passed by.
There’re so many kinds of tape-recorders on sale that I can’t make up my mind _____ to buy.
—How’s your tour around the North Lake? Is it beautiful? —It ________ be, but it is now heavily polluted.
John promised his doctor he _____ not smoke and he has never smoked ever since.
According to the air traffic rules, you ___ switch off your mobile phone before boarding.