Stephen Hawking's crowning achievement was his prediction in the 1970s ________ black holes can emit energy, despite the classical view that nothing can escape their gravity.
A. when B. what C. how D. that
Throughout its early years, what we now call hip hop ________ without even having a name.
A. evolved B. is evolved C. had evolved D. evolves
The pollution is likely to reach its peak on Monday, and some parts ________ heavy air pollution, the environmental watchdog told the newspaper.
A. see B. will see C. would see D. saw
Tea is the main evening meal, traditionally eaten at 5 o'clock in the evening, ________ the diners are not drinking tea.
A. even if B. in case C. as though D. so that
— A young researcher is reported to have died of heart attack, aged only 30.
— ________ I wonder how his family could stand the thought of losing him.
A. How so? B. Forget it. C. Take it easy. D. Really a pity.
People spend half their time dreaming of getting rich, and the rest of their time thinking about all the things they ________ if they got rich.
A. will do B. did C. do D. would do
