Answer:
(VEE-nuh KAY-vuh) A large vein that carries blood to the heart from other areas of the body. The vena cava has two parts: the superior vena cava and the inferior vena cava. The superior vena cava carries blood from the head, neck, arms, and chest.
In the picture attached to this question, the two diagrams above did not show very well but I believe that the first diagram contain four dots, which means that the correct option is A.
Carbon has six electrons, that is why 6 is its atomic number is 6 . In writing electronic configuration, two electrons are usually placed in the most inner shell while the other shells will have 8 electrons each. In the case of carbon which has 6 electrons, only four will remain after 2 electron has been put in its inner shell. Therefore the number of electron in its outermost shell will be four.
The digestion of the food in humans begins in the mouth. In the mouth, the salivary amylase enzyme digests and breaks down a small amount of the starch present in the food. The digestion process begins right in the mouth. and continues till the intestine. The carbohydrates (starch) are the ones whose digestion starts in the mouth.
Hence, the blanks can be filled with 'mouth and amylase' respectively.
There are 3 Oxygen atoms bonded to 1 Nitrogen atom.
Hope this helps!
-Payshence
