The parts of the model shown here illustrate the levels of organization found in the human respiratory system. Number the parts from 1 to 4 to show the correct order from the simplest to the most complex.

B? i feel like this is a trick  

B. nuclear reactions could first occur.

Answerbonded to an amino group(nh2);

The question is incomplete. complete question is attached belowanswer: correct answer is option b  i.e.  solid particles  reason: filter paper has small pores, through which smaller particles can pass through. however, solid particles  have relatively larger size. hence, they are least likely to pass through.