The correct answer for 1 should be electrons.
When you touch a carpet for example, the carpet has electrons that are not as strongly connected. When you rub your feet against it the electrons move to you because your body has vacancies that get filled and this provides the static electricity. When you touch a metal object, the static quickly bursts out and that's why you get the small discharge.
The correct answer for 2 is friction
When the clothes are in there, there is a lot of sliding friction because the clothes are rubbing against each other. This sliding friction causes the things to get charged with static electricity. This happens even outside of a dryer when you have cotton clothes for example and rub them against a carpet.
The correct answer for 3 is true.
The materials that hold them tightly are called insulators and are used for insulating wires for example and prevent electricity from going out. The ones that hold them loosely are called conductors and are great at transferring the electrical energy through wires and similar things. An example of this would be gold.
The correct answer for 4 is attract
Opposites attract while same charges repel. This is similar to how magnets behave which isn't ordinary considering that when you provide something with electricity there is a magnetic field created around it and when you remove the electricity the magnetic field disappears.
