Which category of materials does concrete belong to and why? a. it’s a synthetic polymer because it’s a product of a chemical reaction. b. it’s an alloy because it contains layers of different components. c. it’s a ceramic because it contains substances such as sand and clay. d. it’s a composite because it’s a mixture of cement, sand, and other granular pieces.

Option D, It’s a composite because it’s a mixture of cement, sand, and other granular pieces.

Explanation:

Composite is a mixture which is prepared by blending different substances possessing different physical and chemical properties.  

In case of concrete, the ingredients are -

a) Cement  

b) sand

c) aggregate (granules)  

d) Wire mesh, iron rods or any other substance that has high tensile force.

Here,  the cement acts as a matrix and the gravels and aggregate act as reinforcement. Concrete at the stage of placement is further reinforced by wire mesh or iron rod. Since concrete is good in compressive strength but weak in tensile strength, iron rods provide tensile strength to concrete mix.

Thus, concrete being a mixture of different substances is considered a composite mixture

the offspring would all be white. if the parents are both white flowers then they have the genotype rr, which when crossed results in an all white punnet square.

hypoxemia refers to a below usual concentration of oxygen in the blood, mainly in the arteries. hypoxemia is an indication of an issue associated with circulation or breathing and may lead to various symptoms like shortness of breath.  

the condition is identified by determining the level of oxygen in the blood sample obtained from an artery. it can also be predicted by determining the oxygen saturation of the blood with the application of a pulse oximeter.  

the normal arterial oxygen is about 75 to 100 mm hg. the values underneath 60 mm hg is generally considered with the requirement for supplemental oxygen. the normal pulse oximeter readings generally range between 95 to 100 percent. the values under 90 percent are regarded as low.  

in the given case, the oxygen saturation is measured at 93 percent, hence, there is no need to administer oxygen, that is, one should withhold oxygen.