Present simple vs present continuous

http://www.englisch-hilfen.de/en/exercises/tenses/present_progressive_auxiliaries2.htm

http://www.kico4u.de/english/uebungen/aktiv/preprog1.htm

http://www.focus.olsztyn.pl/en-present-continuous-tense-examples.html#.WNnQD4E18dU

https://www.ego4u.com/en/cram-up/grammar/present-progressive/form/exercises?form04