For Tanks I just spam explode them. They cause a lot of shockwaves so I probably just got lucky.

Thanks, that might work better for some people. I tried spitting too, but not with a crawler, I progresesd to tanks before trying that.

I couldn't figure how to explode a Tank in the 1, but I think it is easier to just land a spit into the scientist. Basically, once he hits the laser beam, spit with a crawler (regular spits just make him cough, but not die) so the arc would loosely follow the scientist's flight path. Timing is important here. Just repeat until you hit him so he dies and lands near the button.

A series of laser puzzles.
1. Explode a tank so that the scientist falls onto the button.
2. Explode one faller around (8) so the other gets pushed onto button, repeat.
3. I forgot, but it was probably Tank explosions again.