Question

you want to place a piece of glass tubing into a rubber stopper after the * 2 points tubing has been fire polished and cooled. this is best done by
lubricating the tubing with water or glycerin.
using a towel or cotton gloves for protection.
twisting the tubing and stopper carefully.
all of the above.
other:
approved eye protection devices (such as goggles) are worn in the * 2 points laboratory
to avoid eye strain.
to improve your vision
only if you dont have corrective glasses.
any time chemicals, heat or glassware are used 4. if you wear contact lenses in the school laboratory,
other:

Explanation:

When inserting glass tubing into a rubber stopper, lubricating with water or glycerin reduces friction, using a towel or cotton gloves protects hands from breakage, and twisting carefully ensures proper insertion. All these steps are standard safety and practical procedures. For eye protection, in a laboratory, chemicals, heat, or glassware can pose risks at any time, so eye protection is needed always.

Answer:

For the first question: D. all of the above.
For the second question: any time chemicals, heat or glassware are used.