I believe it is D solid to gas
I am not really sure are there multiple choice questions if so I need to see them.
Answer:
This is due to lactic acid accumulation in Emma's leg muscles.
Explanation:
In the absence of oxygen in the muscle cells, the cell switches from performing aerobic respiration to lactic acid fermentation. The lactic acid fermentation produces lactic acid as a product, which builds up in the muscle cells of the body causing a burning sensation and pain. This often happens during exercises.
This is the cause of Emma's pain in her lower leg muscles. Lactic acid has been formed and accumulated in the muscle cells of her leg during the exercise with her brother.
If atoms share two , three or more pairs of electrons..they are covalent bonds..for example, methane
if the atoms share only a lone pair of electron contributed by only one of the combining atoms but shared by both ..then it is a coordinate bond ..for example, ammonium ion
When a pathogen comes in contact with your body, it has to breach the first line of defense to get inside. Your skin and mucus membranes are the main barrier here. Mucus traps the pathogens, and then is forced out of your body when you cough or blow your nose. Your skin also secretes chemicals that have antiviral properties, killing viruses on contact. If the pathogens get through that defense, the next line is non-specific immunity cells that patrol your tissues engulfing pathogens. There are other cells that do this, like macrophages, but the dendritic cells are most important for activating the third line of defense in your body.
Dendritic cells reside in your tissues, waiting for an invader to arrive. When they do find one, they engulf it and digest it. After they do this, they select pieces of the invader called antigens and put them on their surfaces. The dendritic cells migrate back to lymph nodes, key locations in your body filled with immune cells. There, they show the antigens, called antigen presentation, to two types of lymphocytes, T-cells and B-cells, activating them for a full immune response.
