Why "would have had" here "We would have had to abandon these cars at the ..."? [Red Mars book] Fragment has confusing grammar: ... “We will have to walk,” Michel said after a while. “We would have had to abandon these cars at the bottom anyway. It’s only about five kilometers. Are your suits fully supplied?” ... Michel talks about the future but uses "would have had" (that is used for the past tenses).

Есть ли идиома в англ. "Вам шашечки или ехать?"

To what "that" is related in the following context? " Italy's economy may have contracted for the past three years but one sector is giving entrepreneurs and investors some confidence: technology start-ups. The growing success of Europe's technology sector has often focused on the powerhouses of the U.K. and Germany but Italy is beginning to gain traction. Italy, the fourth largest economy in the Europe, was one of the worst hit during the financial crisis and the mistrust of large companies ***that*** rose during this period is one of the reasons people are flocking to start-ups, one investor said. " In the last sentence I'm confused whether "that" relates to "mistrust" or "companies". Both could rise, and I cannot understand what? And how to determine it? Is "that" usually refers the first or the second word in a phrase like "some of something"? I have copied this from here http://www.cnbc.com/2015/10/12/italy-europes-next-big-tech-start-up-hub.html

I'm confident more than ever/before [business letter] What word is more appropriate in business letter? Or either of them is good?

"I have been in doubt for some time" or "I was in doubt for some time"? For example: I've read a confusing article about this. So I ... in doubt for some time.

I was reading articles on a web site. Is the preposition correct?

You have already asked this/that During a conversation a person asks me the same question twice. Should i use this or that in the above question? I suppose "that" is more appropriate because it was mentioned already, right?

How has you leaned or did you learn? I know a person that can play piano, I do not know may be he still masters it. But I want to ask how he learned it the start. Should I say "How has you learned it?" or "How did you learn it?" I do not know the exact time so I suppuse I should use the first form, right?

If you stand in line (for tickets for example) and need to leave for a short time. How to say that you will return, so the person after you understand and remeber you?