Here is Exercise Sheet 6 from 40 Beats and Fills Exercises Book 2.
All of the 4 beats and fills exercises are in 6/8 time signature and the emphasis is naturally on beat 1 and 4. In the drum beats, the first beat of the bar usually has a bass drum and beat 4 of the bar usually has a strong snare drum. 6/8 means that there are 6 8th notes per bar.
This is how the emphasis on 1 and 4 looks like if you see them in bold:
1 2 3 4 5 6
On exercise 4, you can see dotted quarter notes (dotted crotchets) in the drum fill on bar 4. The dotted quarter notes each last for one and a half beats, which is the equivalent of half a bar each in this 6/8 time signature. If you think about trying to count these without prior knowledge of playing in 6/8 time, it can throw you off a bit, but if you think about the pulse of the bar (2 pulses per bar, on beats 1 and 4) then they really only feel like they are 1 beat each, along with the pulse.