An animal keeper is studying X-rays of two animals, as shown. X-rays show the internal structures of an animal. Which statement is best supported by the X-rays?

Animal Y has an outer skeleton, and animal Z has a spiny covering.
Animal Y has a spiny covering, and animal Z has an outer skeleton.
Animal Y is a vertebrate, and animal Z is an invertebrate.
Animal Y is an invertebrate, and animal Z is a vertebrate.

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.

Match the types of competition to their descriptions

Why do we perceive objects as retaining their brightness under different lighting levels?