Answer:
C. It may act as an insulator or a conductor.
Explanation:
Group B are the metalloids, so they have properties of both metals and nonmetals.
 
        
             
        
        
        
Answer is: quark.
Quark is a type of elementary particle and a fundamental constituent of matter.
Quarks form composite hadrons (protons and neutrons). Protons and neutrons are in the nucleus of an atom.
Hadrons include baryons (protons and neutrons) and mesons.
There are six types of quarks: up, down, strange, charm, bottom, and top.
 
        
                    
             
        
        
        
Answer:
(B) F⁻, HCOOH
Explanation:
(A) CH₄, HCOOH 
(B) F⁻, HCOOH 
(C) F⁻, CH₃-O-CH₃
The hydrogen bonds are formed when the hydrogen is found between two electronegative atoms such as oxygen (O), nitrogen (N) or florine (F).
O····H-O, F····H-O, O····H-N 
(A) CH₄, HCOOH 
- here methane CH₄ is not capable to form hydrogen bond with water
- formic acid HCOOH can form hydrogen bonds with water
H-C(=O)-O-H····OH₂
(B) F⁻, HCOOH 
-both floride (F⁻) and formic acid can form hydrogen bonds with water
F····OH₂
H-C(=O)-O-H····OH₂
(C) F⁻, CH₃-O-CH₃
-  dimethyl-ether CH₃-O-CH₃ is not capable to form hydrogen bond with water
- floride (F⁻) can form hydrogen bonds with water
F····OH₂
 
        
             
        
        
        
Scientist typically use the international system of measurements, or the metric system. If you mean English as in England, then  yes.<span> The United States' system of measurement is not usually used by scientists.</span>