1 The Mongolian nomads offer/are offering their hospitality very generously.
2 Why do you take/are you taking a photo of that
tree? What’s so special about it?
3 The last flight to Morocco is leaving/leaves at
7:30 pm.
4 Channel 10 is showing/shows a series of
documentaries on Ellis Island this week.
5 According to statistics, the number of homeless
around the world is growing/grows more and
more every day.
6 Benson shoots/is shooting the ball and scores/
is scoring three points for his team.
7 Professor Thomson gives/is giving a lecture on
African tribal rituals this afternoon.
8 Petra is booking/books an aisle seat whenever
she travels/is travelling by plane.

1 The Mongolian nomads offer their hospitality very generously. (это предложение - характеристика, поэтому Present Simple)

2 Why are you taking a photo of that tree? (действие происходит в данный момент => Present Continuous) What’s so special about it?

3 The last flight to Morocco leaves at 7:30 pm. (расписание)

4 Channel 10 is showing a series of  documentaries on Ellis Island this week. (речь только об одной неделе)  

5 According to statistics, the number of homeless around the world is growing more and more every day. (описание происходящего изменения)

6 Benson shoots the ball and scores three points for his team. (при комментировании спортивных событий используется Present Simple)

7 Professor Thomson is giving a lecture on African tribal rituals this afternoon. (действие, запланированное на ближайшее будущее)

8 Petra books an aisle seat whenever she travels by plane. (привычка человека)