不對(duì).
that 如果連接同位語(yǔ)后面應(yīng)為從句,cut in line 為動(dòng)詞短語(yǔ)
it不能做同位語(yǔ)先行詞

所以可以改為I can't stand people who cut in line.
I can't stand it when people cut in line. 
我受不了有人插隊(duì).怎么it不能做同位語(yǔ)先行詞？什么情況？我在考試的時(shí)候是這樣寫的：I can't stand it that someone cuts in line.那樣的話，你的句子不多大問(wèn)題，只是改為1.I can't stand it when someone cuts in line。或2.I can't stand someone cutting in line.會(huì)更好。我想你解釋一下什么叫it不能做同位語(yǔ)的先行詞。1.我想說(shuō)其實(shí)在I can't stand it that someone cuts in line中，it充當(dāng)形式賓語(yǔ)，that someone cuts in line充當(dāng)?shù)氖钦嬲e語(yǔ)，所以根本不是同位語(yǔ)從句。這只是我的看法。但是你要說(shuō)it和that someone cuts in line是同位語(yǔ)的話也行。2.“代詞it可用作同位語(yǔ)從句的先行詞。這個(gè)it常放在某些動(dòng)詞或短語(yǔ)動(dòng)詞后作賓語(yǔ)，同時(shí)兼作其后that同位語(yǔ)從句的先行詞。I owe it to you that I am still alive. 幸虧你，我現(xiàn)在還活著。有的語(yǔ)法學(xué)家把先行詞it后的that從句看作是動(dòng)詞或介詞的真正賓語(yǔ)。一般認(rèn)為，這種it后的that 從句應(yīng)看作it的同位語(yǔ)，因?yàn)樗喈?dāng)于“主語(yǔ)+be+表語(yǔ)”結(jié)構(gòu)。You must see to it that the children don't catch cold.(=You must see to it,and It is that the children don't catch cold.）你要當(dāng)心，別讓孩子們著涼了?！焙冒?，共同學(xué)習(xí)，共同提高，反正我承認(rèn)我是不知道it可用作同位語(yǔ)從句的先行詞。