Answer: A mechanical wave is a disturbance in matter that transfers energy through the matter. A mechanical wave starts when matter is disturbed. A source of energy is needed to disturb matter and start a mechanical wave.
Answer: Different plant structure can increase chances of reproduction by the animals and other living organisms in the ecosystem.
Explanation: Plants like flowers can be pollinated by bees . The bees carry the pollen and this can increase chances of reproduction. Plants like plums that have large seeds can increase chances of reproduction by there fruit falling and rotting so the seed can be forced into soil. Different structures of plants can increase chances of reproduction through the animals, soil around the plant, as well as weather .
The sun's rays hit the Earth at a extreme angle, which causes the days to become shorter, so yes, the sun's rays do hit the Earth at a extreme angle.
Answer: C. High surface tension
Explanation:
Water has high specific heat as it require high heat to raise the temperature of 1 g of water through 
.
Surface tension is the net downward force acting on the surface of liquids due to the cohesive nature of liquids.
Water molecules are bonded by strong hydrogen bonding between the hydrogen atom and the electronegative oxygen atom making it polar. Thus water molecules present on the surface are strongly attracted by the molecules present below the surface and thus act as a stretched membrane.
The surface acquires a minimum surface are and thus acquire a spherical shape.
Conservation
conservation is the act of protecting animals and resources for current and future generations
