11.   Many of the trees have died in recent decades, apparently as a result of the abandonment of traditional pollarding and grazing practices.

12.   But in recent decades the sea walls built behind the marshes as a secondary defence have been blocking their retreat and have squeezed them.

13.   In recent decades, however, it has been weakened.

14.   Erm sea boundaries are now a bit more complex because the law of the sea has been changing erm over recent decades.

15.   Although large corporations have bought a lot of funeral homes in recent decades, most of these businesses are still independent mom-and-pop shops.

16.   Although they may not think of themselves as members, millions of Americans who have accumulated trillions of dollars in savings in recent decades belong to the coalition.

17.   Although that situation has changed in recent decades, Chase employees say a less pronounced bigotry still informs decisions about top jobs at many banks, including Chase.

18.   Although there has been some exchange between the two forms in recent decades, they remain distinct.

19.   An abundance of scientific and medical research in recent decades has challenged that view, with many studies linking mental illnesses to brain function and chemistry.

20.   And that is one problem with the intensive fishing of menhaden, which has escalated in recent decades.