Correct Answer: D. CO₂H₂N₂

Explanation

Let's analyze the molecular geometry of each molecule in the given options.

Key for Molecular Geometry:

• Linear: Molecules with two atoms, or molecules where the central atom has two electron domains (e.g., CO2).

Option A. H2NH3O2

• H2 (Hydrogen gas): A diatomic molecule. All diatomic molecules are linear. (H-H) - Linear.

• NH3 (Ammonia): The central atom is Nitrogen (N). N has 5 valence electrons. It forms 3 bonds with Hydrogen atoms and has 1 lone pair of electrons. According to VSEPR theory (AX3E1), this results in a Trigonal Pyramidal geometry, not linear.

• O2 (Oxygen gas): A diatomic molecule. All diatomic molecules are linear. (O=O) - Linear.

Since NH3 is not linear, Option A is incorrect.

Option B. CO2NH3

• CO2 (Carbon dioxide): The central atom is Carbon (C). C has 4 valence electrons and forms double bonds with two Oxygen atoms (O=C=O). There are no lone pairs on the central carbon atom. According to VSEPR theory (AX2), this results in a Linear geometry.

• NH3 (Ammonia): As determined above, NH3 is Trigonal Pyramidal, not linear.

Since NH3 is not linear, Option B is incorrect.

Option C. H2CH4N2

• H2 (Hydrogen gas): As determined above, H2 is Linear.

• CH4 (Methane): The central atom is Carbon (C). C has 4 valence electrons and forms 4 single bonds with Hydrogen atoms. There are no lone pairs on the central carbon atom. According to VSEPR theory (AX4), this results in a Tetrahedral geometry, not linear.

• N2 (Nitrogen gas): A diatomic molecule. All diatomic molecules are linear. (N≡N) - Linear.

Since CH4 is not linear, Option C is incorrect.

Option D. CO2H2N2

• CO2 (Carbon dioxide): As determined above, CO2 is Linear.

• H2 (Hydrogen gas): As determined above, H2 is Linear.

• N2 (Nitrogen gas): As determined above, N2 is Linear.

All molecules in Option D are linear.

Therefore, the group that contains entirely linear molecules is D.

The final answer is D

Correct Answer: C. Eustachian tube

Correct Answer: C. food production

Correct Answer: A. overpopulated

Explanation

Increasing returns occur when the output increases in a greater proportion than the increase in input. Now, when a country population is experiencing increasing returns, it means its population is rising and may get to a point where it becomes over populated.

Correct Answer: C. Isaiah

Correct Answer: D. 103°

Explanation

πr² = 360°

44cm² = θ

θ = 44/πr²

x 360° = 102.9° = 103°

Correct Answer: C) thyroxin

Explanation

Cretinism is a condition that affects human growth and development. The question is asking what causes cretinism. The options provided are Vitamin A, insulin, thyroxin, and Vitamin C. To answer this question, we need to understand what cretinism is and what each of the options does in the human body. Cretinism is a condition that occurs when there is a deficiency of thyroxin hormone in the body. Thyroxin hormone is produced by the thyroid gland, which is located in the neck. Thyroxin hormone plays an important role in regulating the body's metabolism, growth, and development. When there is a deficiency of thyroxin hormone, it can lead to stunted growth, mental retardation, and other developmental problems. Option A, Vitamin A, is important for vision, immune system function, and skin health. It does not play a role in the production of thyroxin hormone, so it is not the cause of cretinism. Option B, insulin, is a hormone that regulates blood sugar levels in the body. Insulin does not play a role in the production of thyroxin hormone, so it is not the cause of cretinism. Option C, thyroxin, is the correct answer. As mentioned earlier, cretinism is caused by a deficiency of thyroxin hormone in the body. Option D, Vitamin C, is important for immune system function, wound healing, and collagen production. It does not play a role in the production of thyroxin hormone, so it is not the cause of cretinism. In summary, the correct answer to the question is Option C: thyroxin. Cretinism is caused by a deficiency of thyroxin hormone in the body.

Correct Answer: D. stood

Explanation

bull; /b?l/

stood; /st?d/

Correct Answer: B. use of parasites and predators

Correct Answer: A. hierarchical and centralized administration