why is alley cropping considered a sustainable farming practice?

a)it requires farmers to know best practices for only one crop.

b)it allows farmers to meet current needs while preserving resources.

c)it is less expensive than conventional farming.

d)it allows farmers to focus on selling their crops locally.

Alley cropping considered a sustainable farming practice because it allows farmers to meet current needs while preserving resources. Therefore, the correct answer to the question is option b.

Explanation:

Alley Cropping is defined as the type of cropping in which the long trees are planted at the boundaries having maximum distance between them and the small shrubs and herbs are planted in between the space between them.

This type of farming is very essential and beneficial for the farmer and the environment. It is so because it utilizes all the land for farming purpose and at the same time it allows the farmer to meet his all the needs of the current situation and also saves much input for the future use.  

thrombocytopenia, which is a deficiency in blood platelets, can cause bleeding and bruising in the dermis similar to senile purpura. other possible causes include: exposure to ultraviolet rays and aging skin are common causes of senile purpura. senile purpura may also be a sign of collagen loss in the skin and bones.

water is a polar molecule. a chemical bond is a force of attraction between atoms or ions. bonds form when atoms share or transfer valence electrons. atoms form chemical bonds to achieve a full outer energy level, which is the most stable arrangement of electrons. so, false

explanation:

in h2o molecule, two water molecules are bonded by a hydrogen bond but the bond between two h - o bonds within a water molecule are covalent. the greater the electronegativity difference, the more ionic the bond is. bonds that are partly ionic are called polar covalent bonds. nonpolar covalent bonds, with equal sharing of the bond electrons, arise when the electronegativities of the two atoms are equal.