Sublimation
Sublimation is where a solid changes directly to a gas state. It's technique is usually use to purify substances. The dry ice is one of the example of using sublimation in daily life, dry ice is use to keep ice cream cold when it is not refrigerated.
Motion of a Pendulum
A pendulum consists of a metal bob suspended by a string from a fixed support. It is normally used in clocks and to measure time. The length of the string in a pendulum also affects its swing. The longer the string, the longer time the pendulum takes to make one swing.
Complex Machine
Before a complex machine, yous should start with the basic first which is simple machine, the basics of simple machine consists of lever, pulley, wheel and axle, inclined plane and gears. In higher levels, it's divided into more complicated parts. The complex machine is a combination of some or all of them, an airplane is one of the example.
Structure of the Earth
The earth consists primarily of the crust, mantle and core. The crust is the thinnest, top layer of the Earth. The mantle is the layer beneath the crust. The core is the innermost layer of the Earth's Structure.
Now, I think that you're ready, here's the video that me and my group mates had made: