1．Trains play an important part in transporting(transport) goods and passengers in China.
2．When the boss came in, the workers pretended to_be_working(work) hard on their machines.
3．Some teenagers drop out of school and wander around/about the street all day with nothing to do.
4．The lake seems calm, but there are hidden(hide) dangers, especially for those who can't swim.
5．Parents hope that their children can be educated in a relaxing (relax) and active atmosphere.
Ⅱ.单句改错
1．The tower dated back to the Warring States is well worth visiting.
dated→dating
2．I picked up a copybook yesterday marking with name and class.
marking→marked
3．There will be a huge parade in the celebration of National Day every year.
去掉the
4．He planted two trees last year, both of them are growing well.
them→whom或both前加and
5．It is no need to take a taxi since it's only five minutes' walk from here.
It→There
