"Which level 4 raids can be done by 2 people?"

#PokemonGO: My son and I play together. Due to schedules, we often cannot participate in the coordinated raids so we have to try duo raiding. We can take all of the level 3 raids, but I don't know where to start for level 4. Are any doable with only 2 trainers? via /r/TheSilphRoad http://ift.tt/2vkl8ty