12.1 The acid in the stomach destroys microbes.
12.2 The skin prevents microbes from getting into the body.
12.3 Sticky mucus in the lungs nets microbes, and then cilia span it out of the lungs
13. D. Skin
14. False - Mucos prevents microbes in certain organs
15. False - It is a colorless fluid.
16. A. Bacteria
17. B1
8. False - Thymus in the anterior part of the chest directly behind the sternum between the lungs
19. C. Red blood cells
20. False - Bone marrow produces the known blood cells
21. True
22. False - It starts in the bone marrow.
23. True
Answer:
Early humans that likely evolved from Cro-Magnons - <u>Homo</u><u> </u><u>sapiens</u><u>.</u>
These are my suggestions for the final part of your homework: 6 - A; 7 - B; 8 - D; 9 - C; 10 - C.
The exercise follows the Sequence of Tenses rules.
For 2 the answer is C because you have two simultaneous actions which need same tense like, the Present.
