When people climb with a paid guide, it's clear who should be in charge of the group's safety. But when unpaid amateurs climb together, things becomes murkier.
assert comp(shift(3,4), shift(1, 3)) == comp(shift(1,4),shift(2,3))
，推荐阅读新收录的资料获取更多信息
这背后是一条清晰而深远的商业脉络。。业内人士推荐新收录的资料作为进阶阅读
Relatives of 26-year-old Erfan Soltani, who was detained last week, have told BBC Persian he is due to be executed on Wednesday.
Format errors with context. Show the source line, underline the relevant