`1` They're such easy questions that everyone can answer them
`2` The boy whose parents died in a traffic accident will receive some money to continue his study
`3` Motorbikes are being produced in Vietnam
`4` If I had been there yesterday, I would have known who he was
`5` Unless you try hard, you can't pass the examination
`6` The more they spent money the harder they had to work
`7` The cover was thought to have been make of iron
`8` He went to London where had lived when he was a a boy
`9` Because Jane was sick, Jane was absent from class
`11` The package was so heavy that Peter couldn't carry it.