Hello there Jonnromeroo, thank you for asking a question here on Brainly!
You Asked ➤ Which of the following processes begins when a star enters the main sequence?
↴ OUR CHOICES ↴
A: Nuclear fission
B: Nuclear fusion
C: Condensation of a nebula
D: Appearance of a supernova
------------------------------------------------------------------------------------
Answer ➤ B: Nuclear fusion
Explanation: When a star begins the process of being created, it is hot and dense. Really hot and dense! It begins to start fusing with helium which is the start of its main sequence called nuclear fusion.
I hope this answer is helpful to you, but please let me know if you have any other questions regarding it.
<em>- Qamar </em>
The human immunodeficiency virus (HIV) that causes the disease known as aids selectively infects helper T cells (CD4+).
This retrovirus also infects macrophages and dendritic cells. When CD4+ T cell numbers decrease below a critical level (due to the killing of this cells with different mechanisms), cell-mediated immunity is lost. As a result, the body becomes progressively more susceptible to infections, leading to the development of AIDS.
<span> HIV can be transmitted only via body fluids like blood, semen, pre-seminal fluid, rectal fluids, vaginal fluids, and breast milk, which means that people usually get or transmit HIV through sexual behaviours and use of the needle. For HIV infection, these fluids must come in direct contact with a mucous membrane or damaged tissue. Another way is to be directly injected into the bloodstream (from a needle for example).</span>
Explanation:
The tick carries harmful bacteria that was released into Charlie's blood.
So, I can conclude that:
tick> indirect, bacteria direct
Hope this helped! Let me know if this is incorrect.
Answer:
C Water flowing downstream is held up in a reservoir behind a dam. Some water moves down channels through turbines connected to generators which produce electricity
Explanation:
Good explanation.
I kinda remember it and I think it's 60%
