You are driving on a road with reversible lanes that are marked with overhead lane signals; choose an
a. you may drive in a lane under a green arrow.
b. you must drive in a lane under a green arrow only when you are passing slower traffic.
c. you must never drive in a lane under a green arrow.

jupiter is mainly composed of hydrogen and helium just like a star. spectral analysis of jupiter has revealed that in addition to hydrogen and helium, the planet is made of water, methane and ammonia. those elements are in trace amounts. the core of the planet is thought to contain some rock and metallic hydrogen. i hope this will give you the answer to your question! : d

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.