I have been collecting sells since 2008.（改为否定句）

I have been collecting sells since 2008.（改为否定句） We have been waiting since 8.00(改为否定句） she has been reading I like collecting stamps and singing.（改为否定句） I have been teaching English since 1986.改为同义句 I have already been to beijing 改为否定句 i have already been to ocean park.改为否定句 i have been to australia (用NEVER 改为否定句 They have been collecting shells for there years.（改为同义句） I have been collecting stamps since I was 7.Now I am 12.（合并为 I’m interested in collecting stamps.(改为否定句) I have already been to Water World with my parents.（改为否定句） .I have been collecting them 1 I was eight years old 当since