Scientists generally agree that Earth's climate will warm up over the next 50 to 100 years __________ it has warmed in the 20,000 years since Ice Age.
33._________ in some rural schools that the teacher is even unable to walk through the rows of desks.
32.World leaders at the G20 summit conference in London decided to_______$1.1trillion(万亿) to supporting world economic growth and trade.
30.When you finish your work, don’t forget to put the tools back where they ________.
29.The police tried to get some clues from the suspect, but he remained________
27.In hot weather, an old tyre can break again easily _____it’s mended.