Question

Two lines that do not intersect are parallel.

Short answer

The blank should be filled with sometimes.

Step-by-step solution

Step 1. Determine the possibilities

The provided statement does not represent a true statement in all the cases.

Step 2. Analyze the possibility

Some lines do not intersect with each but they are not parallel like skew lines these lines because these lines present on the different planes so these lines never intersect with each other along with this these are not parallel.

Step 3. Make the conclusion

The word suitable for the blank is sometimes.