Given a travel related situation, and given a specific question about the situation, summarize the question into a title

Example Input: When paying by card flight attendants usually ask to see your ID, to verify that the card in fact belongs to you. However it seems weird to me that pretty much no other merchants ever ask to see your ID, even when conducting purchases for thousands of euros (e.g. at IKEA).

So why do airlines insist on verifying your ID when paying by card? I understand that there's (usually) no Internet to verify the card balance on the plane (as suggested by TonyK), but how would one's ID help them out in case the card is empty?

Example Output: Why do flight attendants ask to see your ID when paying by card on the airplane?

Example Input: I have a newborn in Cambodia and finally got to the point where I have a Lithuanian passport with Cambodian exit visa stamped in, valid for 7 days. I will need to leave the country with the baby and then come back and get him an E class visa upon entry, which then can be extended forever. I spoke about this yesterday at the immigration department and they seemed to be ok with the plan below. However from my personal experience I know that things at the border don't always run so smooth...

This one is tricky, as normally no one does visa runs in Cambodia since you can get indefinitely extendable E class visas. Still it is worth asking (and I have a slight Asian border-crossing phobia). I am planning to cross the Vietnamese border with the baby, while his mom will wait at the border to save on Vietnamese visa. Also, her Cambodian visa is 3 month single-entry. Then I get Vietnamese visas for me and the baby and then head ASAP back (baby is 3.5 months old and he has boob addiction. I have a bottle of formula, but he doesn't like it much. Also he hasn't been away from mom more than 10 feet ever). When doing visa runs is it wise to stay for some time in Vietnam, or can I cross immediately back and no one is going to blink an eye?

How long do I need to stay in Vietnam when doing a visa run from Cambodia for a baby to be on the safe side?

Example Output: How long do I need to stay in Vietnam when doing a visa run from Cambodia for a baby?

Example Input: I'm considering booking two flights on separate tickets through Frankfurt Airport. How much time should I include for a transfer between the terminals 1 and 2?

I will be flying Schengen to non-Schengen, with luggage.

Example Output:
How long does it take to transfer between Frankfurt Airport's terminals?