a) 1.present simple
2.present continuous
3.present simple
4.present continuous
b) Present simple:excuse, do i take, need, I am, are, usually come, live, comes
Present continuous:are you waiting
c) 1.We use the present simple for permanent situations and routines
2.We use the present continuous for activities that are happening at or around the time of speaking.
d) 1.In first sentence is used present simple because is a permanent situation.
2.In second sentence is used present continuous because represent an activity that is happening at the time.
