D iscuss with your classmates whether there are any problems in the following letters and how you can improve them.then contrast your improved letters with the original ones. Dear sir: You can have a green,weed-free lawn this summer with a revolutionary new fertilizer.and we do all the work! Once a week,our trained experts will visit your home to apply Green-Gro,a liquid fertilizer developed by Foster Tree&Lawn.It kills weeds and strengthens the root fibers of the grass.It works in both shady and sunny areas and is particularly effective in our climate zone.Green-Gro is safe to use around pets and birds(but keep kids away until the liquid dries). All you have to do to have a beautiful lawn for the entire season is to water it and keep the grass cut.Green-Gro will do the rest. If you act now,you can get an"early-bird discount"of 25%off Green-Gro's regular price.Your green lawn will be a cool oasis all summer. Sincerely, David