By the middle of the 21st century , the vast majority of the world’s population ________ in cities rather than in the country.
16.-Governments at all levels have to take measures to improve the quality of basic education. -Exactly. _________, students' homework must be greatly reduced.
15.A government, which is responsible for society, must_________to its people how important the method is to prevent AIDS.
14.Mum, you really need to have a. rest! You_________in the kitchen ever since you came back home three hours ago.
13.A new simplified desktop computer has been developed for people aged over 60 to make them _________with PC and the Internet.
12.We have to study for a bright future, so we have to lose some sleep_________we're worn out.