Son los principales elementos que se emplean en la hoja de cálculo de Excel pueden ser números, fechas y horas.

answer: when the substance contain the two parts (polar and non-polar) like soap.

explanation:

soap is produced from the basic hydrolysis of ester "saponification", it is considered as a salt of hydrocarbons. the soap molecule contains the two parts: a polar group   (-coo-na+) and a non-polar group (r-hydrocarbon part). the polar group is called the head and the tail is the non-polar group. the polar group is hydrophilic in nature (water loving) and the non-polar group is hydrophobic in nature (water repelling).the polar/non-polar nature of a substance is useful that it can dissolve the non-polar substances by the polar part and also can dissolve the polar substances by the non-polar part. it commonly used in detergents and soaps.

To level up and to reward the people who answer your questions 

My hair is auburn not red or brown.

Ibelieve the answer is: b.  use a different transition for every slide to keep the audience's attentiona. that would make it boringc. sound effects might be distracting and some people might find it annoyingi hope that : )