What is a definition of material creep? (Standard creep here, not static fatigue)

For standard plastic injection molding and extrusion machines, we have a kneed screw driving the feedstock material through the heater barrel. What is the main purpose of this screw? 

Which of the following statements about portable fire extinguishers is MOST accurate? 

Compression molding is slow but has better properties than injection molding for the same material

In injection molding, what is the most important parameter in controlling the anisotropy of the material? (Hint: Remember that injection molding is typically only used for thermoplastics)

Define “subtractive manufacturing”

Which of the following types of smoke detectors works on all types of fires and is best suited for living rooms and bedrooms?

According to NFPA 25: Standards for the Inspection, Testing, and Maintenance of Water-based Fire Protection Systems, fire hydrant inspections should be performed: 

When allowing hot work operations to proceed, at least one fire extinguisher with a minimum 2-A:20-B:C rating should be located within 30 ft. of where the hot work is being conducted.

What are the five necessary conditions for a dust explosion to occur?