________ global temperatures rising, the UN Climate Change Conference was held in Cancun(坎昆), Mexico last year.
They paid fifty percent of _____ they were able to earn to the state.
---You look tired after _____ search for the missing boy.---Yes, I prefer to head for _____ bed as soon as possible.
The new tax policy only affects people on yearly incomes over 120,000, _______ ,the very rich.
---Which of the three optional courses did you like best, Joe? ---To tell you the truth, I didn’t like _______ of them.
Kate ________ on her new novel, which is supposed to come out next month.