Answer the following puzzles:

1.Almost everyone used it.Never in front but always at the back.Sometimes it's planted with 2 rows with it and sometimes with 1 row.Has a twin but appears when only upgraded.Always picked but rarely picked in night and fog levels.Who is it?

2.It has a single tooth but gives something that you can collect but never gives the most precious stone ever.It has only one color when you are playing,but in Zen Garden it has many colors.Who is it?

3.It is a tall plant.It always planted in font but never at the back.Has a similar but It's smaller and more circlier than his father.Who is it and his similar?