Which describes the interaction?

1. Two abiotic factors are interacting.

2. Two biotic factors are interacting.

3. The tree is abiotic and is interacting with a biotic factor.

4. The tree is biotic and is interacting with an abiotic factor.

What was dr. willem johan kolff’s first step in using the scientific process to invent the hemodialysis machine? he built the machine and tried it with various patients, collecting data about its effectiveness. when a patient’s kidneys failed, he wondered if it would be possible to perform kidney functions with an external machine. he researched and collected data about numerous patients who exhibited symptoms of kidney failure. he drew conclusions from studies of various symptoms of kidney failure, and drew a design for the ideal external blood-processing machine.

Which of the following particles always has a positive charge? a. electronb. neutron c. proton d. ion

Which of the following types of stars are dim but can have high surface temperatures? giants main sequence stars supergiants dwarfs