Which of these describes the use of hieroglyphics and pictographs in ancient times? Select all correct answers. a. They were often drawn on walls
b. They were made using modern art tools
c. They record events and cultural histories
d. They are a form of signal that can be heard.

Say what answer you choose.
Explain your answer.
Say why you didn't choose the other ones and instead you choose (what you think or know it is).
If you give me the correct answer and you know it is correct then I'll give brainiest to you. (only if two people answer).

Subject : Science
.-/I picked a random subject./-

How do hydroponic plants differ from nonhydroponic plants? a.) hydroponic plants can grow in a dryer soil. nonhydroponic plants grow in moist soil. b.) hydroponic plants grow on other plants and are known as air plants. nonhydroponic plants do not grow on other plants. c.) hydroponic plants can only grow in rain forests. nonhydroponic plants cannot grow in rain forests. d.) hydroponic plants are grown without soil. nonhydroponic plants are grown in soil.

The position of a dragonfly that is flying parallel to the ground is given as a function of time by r⃗ =[2.90m+(0.0900m/s2)t2]i^− (0.0150m/s3)t3j^. a: at what value of t does the velocity vector of the insect make an angle of 34.0 degree clockwise from the x-axis? b: at the time calculated in part (a), what is the magnitude of the acceleration vector of the insect? c : at the time calculated in part (a), what is the direction of the acceleration vector of the insect?

Follow these directions and answer the questions. 1. set up the ripple tank as in previous investigations. 2. bend the rubber tube to form a "concave mirror" and place in the ripple tank. the water level must be below the top of the hose. 3. generate a few straight pulses with the dowel and observe the reflected waves. do the waves focus (come together) upon reflection? can you locate the place where the waves meet? 4. touch the water surface where the waves converged. what happens to the reflected wave? 5. move your finger twice that distance from the hose (2f = c of c, center of the curvature) and touch the water again. does the image (the reflected wave) appear in the same location (c of c)? you may have to experiment before you find the exact location. sometimes it is hard to visualize with the ripple tank because the waves move so quickly. likewise, it is impossible to "see" light waves because they have such small wavelengths and move at the speed of light. however, both are examples of transverse waves and behave in the same way when a parallel wave fronts hit a curved surface.