I will try Otter Browser. Many thanks for this tip, oleoleole!!! I tried many Browsers, but there is no other perfect Browser than Opera with Presto. Currently I use Opera version 12.14 and not version 12.16 because of the problem with the selection of the standard search machine. It's possible to avoid this problem with a trick, but actually this problem is not a bug in Opera:

Release note to version 12.15.:
General and User Interface:

• Fixed an issue where the search bar's default engine could be overridden by third-party apps.

It was purpose! I guess that Opera was paid by Google to do so. When you want to use a standard search machine other than Google, you have to use version 12.14.! That's really annoying. In my opinion Opera is dead.