When mr. valdez thought his 1-year-old daughter had fallen down the stairs, his heartbeat accelerated, his blood pressure rose, and he began to perspire heavily. mr. valdez's state of arousal was activated by his nervous system.

the sympathetic nervous system

Explanation:when the right signal is sent to the brain, there's a rise in catecholamine level causing the narrowing of blood vessels and a consequent rise in blood flow/pressure

he is very short, and he can only reach halfway up on the elevator buttons. but on a rainy day, he has his umbrella with him, and he uses it to poke the button at the top.

blue stars have the highest surface temp

stellar distances are usually expressed in light-years

the measure of a star's brightness is called magnitude

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