The body's first line of defense is the mucous membranes
Answer:
The cause of their decline is most likely due to a combination of factors cited in the media
Explanation:
Answer: 5.300 j
Explanation:
i answered it and got it right
Answer:
The three-chambered hearts of amphibians and nonbird reptiles are facultative, allowing variation in blood flow through the heart.
Explanation:
In Anatomy, cardiac cycle can be defined as a complete heartbeat of the human heart which comprises of sequential alternating contraction and relaxation of the atria and ventricles, therefore causing blood to flow unidirectionally (one direction) throughout the human body.
Generally, the cardiac cycle occurs in two (2) stages;
I. Diastole : in this stage, the ventricles is relaxed and would be filled with blood.
II. Systole: at this stage, the muscles contracts and thus, allow blood to be pushed through the atria.
All amphibians and reptiles except for crocodiles (having four-chambered heart) have three-chambered hearts, which typically comprises of a partially divided ventricle and two atria.
Hence, the correct statement about the three-chambered hearts of amphibians and nonbird reptiles is that, the three-chambered hearts of amphibians and nonbird reptiles are facultative, allowing variation in blood flow through the heart due to the partially divided ventricle.
Answer:
Aluminium - Open Pit (or Open Cut Mining)
Tin - Placer Mining
Copper - Underground Mining
Explanation:
Open Pit Mining: Another name for open pit mining is <em>open-cast</em> or <em>open cut </em>mining. In simple terms, this involves removing topsoil or earth in order to expose and access the minerals beneath them. This type of mining is usually applied when the mineral deposit is close to the earths surface.
A typical feature of open-pit mines is that they leave very wide open pits though the actions of excavators.
Besides Aluminium, other types of minerals which can be mined using this method are: Bitumen, Clay, Coquina etc
Placer Mining
Placer deposits (that is minerals that have been concentrated on a location by weathering are usually accessed by the use of water. This method is mostly connected with the retrieval of minerals within water bodies. Water is used to dig up, and collect heavy minerals from such deposits.
Underground Minning
The entrance into underground mines can be horizontal or vertical.
An underground mine is simply a mine that is beneath the surface of the earth.
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