1. Due to the malleability of the steel being great (flexible), it is easy to bend. However, it is not easy to elongate. Exerting a horizontal strength on the original, vertical steel structure makes it easier to bend, as well. Though, for cross-bar reinforcement, exerting horizontal strength will distribute the power into lengthening and shortening strengths, thereby reducing overall integrity (strength). As such, using structural cross-bar reinforcement for the bookcase will make it stronger.

2. Using concrete and stone as building materials makes the pressing down, but not extension of an object more durable. Should these two materials be used to build archways or arch bridges, each deformation will be passed to the pillars on either side, and then to the ground. Every piece of the structure will, therefore, only sustain a pressure height-wise [vertical], but not lengthwise [maybe horizontal]. Therefore, using concrete and stone to construct archways and bridges demonstrates the durability of a strength pressing down.

3. Steel is an alloy consisting of iron and carbon (5%). Carbon, with its small atomic structure, can be placed in vacant spaces within an atomic arrangement. This makes it so iron atoms barely slide. Thus, carbon decreases the malleability of iron and enhances its hardness.

4.

1) Alum will generate cotton material when adding into water. It has the capability of capturing (Brownian motion) the impurities and some microorganism which exist in the water. When the aggregation becomes bigger, the Brownian motion stops, it starts to precipitate; therefore, making water clean.

2) To sterilize.

5. Water with nutrients flowing through it will breed bacteria, which, in turn, consumes oxygen in said water. This makes it so other creatures find it difficult to survive. Furthermore, this tends to destroy surrounding environments.

6. When the capacity of the electrical energy transmission is the same, the higher the voltage, the lower the electrical current. This makes less waste in energy use.

7. When the movement of atoms and molecules is faster, the temperature of the microcosmic world will increase.

8. Resonance is the tendency of a system to oscillate larger amplitudes at similar frequencies. For example, when you push a child on a swing, operating at a coordinating frequency can make the swing go higher. For another example, soldiers do not march in-step when they cross a swinging bridge.

9. A dehumidifier, like a refrigerator, has refrigerant, pipes, expansion valve, and compressor, so with electric power input, it can create a very hot tube region and very cold tube region. In addition, it based on the fact that warm air is more capable to carry water than cold air. A dehumidifier suck in air and let the air to flow through the cold part of tube, then water precipitated (separated) from air; before the dryer is release back to room, it is warmed up by forcing the air passing through the hot part of the tube. This cycle therefore keep removing water from air.

10. The general principles of the amplifier are that a razor-thin power or signal input controls a powerful force of signal output. For example, a strong current or currents, blocked by a sensitive value while the value switches order-taking from a weaker force to an original control, will create a zoom-effect.