A substance that enters Earth's cycles and does harm to living things is

A. oxygen.

B. freshwater.

C. a pollutant.

D. hydrogen

An ecosystem cannot repair itself after a volcanic eruption after a flood after a tornado after a houseing development is built

Give one example of why a bird's beak is designed especially for the type of food it eats.

Why can oxygen diffuse across a cell membrane but a protein cannot

Glue secreted by seaweed or barnacles is an adaption to which of the following environments? deep ocean rocky intertidal shallow oceanic sublittoral

M: Weather Flag this Question 10) What is the relative humidity of a sample of air that has a dry-bulb temperature of 20°C and a wet-bulb temperature of 11°C? A) 9% B) 2% C) 17% D) 30%

Animal cells are permeable to water and urea but NOT to sucrose. The inside of a cell contains 1 M sucrose and 1 M urea and the outside 1 M sucrose and 2 M urea. After the system reaches equilibrium, what changes are observed?

How has human activity impacted the evolution of the peppered moth?

Which feature of sugarcanes suggests that they are stems? The presence of scaly leaves and axillary buds A high quantity of sugar The development of adventitious roots

How was the wildlife affected by hurricane sandy in 2012

What is the difference between a leading and lagging strand?