Answer:E. coli: Cytosine- 26, Thymine-24
Human: Guanine-20, Cytosine-20
Ox: Guanine-21, Cytosine-21, Thymine-29
Explanation:
Chargaff's rules state that in a given DNA molecule the percentage of Adenine %A is approximately equals the percentage of Thymine %T and the percentage of Guanine %G is approximately equals the percentage of Cytosine %C.
Answer is 
E. coli: Cytosine- 26, Thymine-24
Human: Guanine-20, Cytosine-20
Ox: Guanine-21, Cytosine-21, Thymine-29
 
        
             
        
        
        
Answer:
B. a graduated cylinder to measure 30 mL of water for each plant daily
Explanation:
<em>Option A is incorrect because an electronic balance is used to measure the mass of an object and not the volume.</em>
<em>Option C is incorrect because a metric ruler is used to measure the dimension of objects and not the mass.</em>
<em>Option D is incorrect because a thermometer is used to measure temperature and not pH.</em>
The correct option is B. A cylinder is applicable in the measurement of volume of liquids.