I. Complete the second sentence so that it has similar meaning to the first sentence.
1. America celebrated Thanksgiving Day on the fourth Thursday of November in 1864.
--> Since 1864 ......
2. Help me do homework, and I'll take you to school.
--> If......
3.Too much use of electric lights in cities may cause light pollution.
--> Light pollution may result............
4.Most people in this village had left before the volcano erupted.
--> After.................
