多久 (duō jiǔ): (of time) how long? (pronoun) — Meaning & Stroke Order

How long do you think the lifespan of this new material can be?

How long did your last trip take, and which places did you visit?

What is the specific validity period of the visa you applied for?

How long can the inventory in your warehouse support the order demand?

At most, how long can you stay here? I need to make arrangements in advance.