21 weedicide
22 lactobacillus
23 prokaryotes
24 nylon, rayon, Dacron™, and Orlon™.
25 carbon hydrogen etc
26 kJ/kg
27 The atmospheric pressure is the weight exerted by the overhead atmosphere on a unit area of surface. It can be measured with a mercury barometer, consisting of a long glass tube full of mercury inverted over a pool of mercury
28 megaphone
29 organelles