翻译一句They must've had very strong stomachs

A： his visitors seemed to go back for more. (交待一点背景：host提供的晚餐经常是一些奇怪的食品)

B: They must've had very strong stomachs(什么意思呀？)

They must have arrived by now,haven't they? they've got a toothache还是they have a ...还是they've had a ...? 翻译we must try hard to protrct there rare animals;otherwise they'll die out in a few years. 翻译：If they do this, they will learn the hard way that spending must be done within a budget. 1.______useful the information they've given us is! 翻译:let's get off the ship.和It must be in the treasure box.you've got to look for it carefully. They've been _____ it for hours, but they still can't agree 翻译:When you go outing with your sisters,you must see to it that they are safe. they must为什么they不用加are了？ must的否定句？