Different types of rock in a rock wall are usually easy to tell apart because of what

Sedimentary rocks such as limestone or shale are hardened sediment with sandy or clay-like layers (strata). They are usually brown to gray in color and may have fossils and water or wind marks. Metamorphic rocks such as marble are tough, with straight or curved layers (foliation) of light and dark minerals.

Explanation:

hygrometers and hair thermometers (often found as part of hygrometers/psychrometers) can be used to measure humidity. barometers are used to measure atmospheric pressure, while anemometers are used to measure wind speed. so the 2nd and 4th choices should be the correct answers.