1．He crossed the street and walked alongside (沿着……的边) Central Park.
2．Waving (挥手) goodbye to them on the platform, I felt happy for them and wished them a safe journey.
3．In conclusion, people around the world should be aware of the real situation of water shortage, protect the present water resources and explore potential (潜在的) ones scientifically.
4．I would appreciate it very much if you could give us some precious (宝贵的；珍贵的) advice on how to improve our online English school.
5．Only when one is in good health can he guarantee (保证) efficient learning.
6．Studies indicate an increasing threat (威胁) from extreme weather, such as tornado, typhoons, drought, flooding, sandstorm, hailstorm, and so on.
7．I consider it necessary for the government to arouse (唤醒) public awareness of protecting environment.
8．To students, you'd better choose the activities which interest you and suit (适合) you.
