Which observation does NOT necessarily indicate that a chemical reaction has occurred?

A. formation of a precipitate C. production of a gas
B. evolution of heat and light D. change in shape

Cloud formations disappear as the air moves slowly towards the leeward side of a mountain because subsidence warms the air. when air is warmed, moisture is evaporated. evaporation leads to the dissipation of clouds in the lee of mountains.

ANSWER: Horizontal communication

When the accounting manager communicates to the purchasing manager the dollars available for purchases in the current month, this is an example of Horizontal communication.

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