call upon
phrasal verbcall on/upon somebody (formal)
to ask or demand that somebody do something 请求，要求，要（某人做某事） She called on the government to hold a vote. 她呼吁政府举行投票。 I feel called upon (= feel that I ought) to warn you that… 我觉得我应该警告你…
to formally invite or ask somebody to speak, etc. 正式邀请，要求（某人讲话等）；恭请