BeginnerExercise271/Solution

Simple  

ProtoDeuteric: takees the corner eye away, and white is either too slow or lacks the liberties necessary for a proper response. I think "a" is also possible, but there is potential ko considerations that make the situation more messy than it needs to be.

Follow-up  

And make sure to follow it up correctly.

Other Follow-up  

togo: If here, then on a or b kills by damezumari.

And another one  

togo: If here, then kills by leaving only one eye.

Ko for life  

Anonymous: leads to ko. If white wins the ko, she will capture and live with two eyes at and . If black wins the ko, he will connect at the marked spot and thereby kill the white group.