Which of the following is the most sensitive and reliable procedure for extracting combustible residues?

Question 5 options:

high-performance liquid chromatography

gas chromatography

passive headspace extraction procedure

direct headspace extraction procedure

a polar bond is formed when electrons are shared unevenly between atoms

under a microscope, cancer cells may look very different from normal cells. they often have different sizes and some may be larger than normal while others are smaller. cancer cells are often abnormally shaped and the control centre of the cell (the nucleus) may have an abnormal appearance.

i think? ?

the correct answer to this question is 2