Is the problem true of false
Explanation:
Tarbuck, Earth's crust is made up of several elements: oxygen, 46.6 percent by weight; silicon, 27.7 percent; aluminum, 8.1 percent; iron, 5 percent; calcium, 3.6 percent; sodium, 2.8 percent, potassium, 2.6 percent, and magnesium, 2.1 percent
About 29% of Earth's surface is land consisting of continents and islands. The remaining 71% is covered with water, mostly by oceans but also lakes, rivers and other fresh water, which all together constitute the hydrosphere.
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Earth.
Almost 99% of the minerals making up the Earth's crust are made up of just eight elements. Most of these elements are found combined with other elements as compounds.
The presence of vertebral column or notochord at any stage of life in any organism is the characteristic of vertebrate.
Explanation:
An animal is vertebrate if it fulfils the following criteria:
Presence of vertebral column or notochord.
Presence of endoskeleton or backbone.
The spinal cord runs above the vertebral column.
Humans embryo has notochord which becomes a vertebral column.
The alimentary canals end in the anus.
Mouth is present ta the anterior side of the vertebrate.
Have legs, fins or wings for movement.
Presence of a nervous system and sensory organs.
Presence of skin, lungs or gills.
Presence of a circulatory system.
Vertebrates include fish, amphibians, reptiles, birds and mammals.
Kelp can be described as <span>fast growing algae. The correct option among all the options that are given in the question is the fourth option or option "d". It is a unique kind of an algae that has the capability to grow 2 feet in a day under right conditions. I hope that this is the answer that has come to your great help.</span>
Answer:
it is called tympanostomy tubes. they also help to equalize pressure
