先遣的英文：
sent in advance

参考例句：

Hal was like my advance man.
哈尔好比是我的先遣人员。

To serve as an advance person for a trip to be made by a politician or a dignitary.
做先遣人员；先行准备作为政治家或政界要人预期行程的先遣人员

Blix and his initial team of 30 are now in Iraq.
目前,Blix已带领30名先遣队员进入伊拉克。

The advance team was at the peak of their self-confidence, honed by political campaigns to a razor-edge
这个先遣班子，由于在竞选运动中的磨炼，正是锋芒毕露达到了自信的顶峰。

sent是什么意思：
v. send的过去式及过去分词

Full details will be sent on request.
有详细材料备索。

On this occasion the lodge sent a carriage.
为了当晚的演出，支部派了马车来接她。

The patient was sent to the operating room.
这个病人被送进了手术室。

They sent their children to private schools.
他们送孩子们上私立学校。

The man sent a wire back.
男人回了个电报。

advance是什么意思：
v. （使）前进；发展；推进；预付；提出；提前；进展；上涨；被晋升；贷（款）
n. 前进；发展；预付款；增长
adj. 预先的；先行的

Prices are advancing.
各种物价都在上涨。

The advance was sounded.
进军号吹响了。

Petroleum is on the advance.
石油价格正在上涨。

The work is not advancing.
工作没有进展。

an advanced stage of illness; a person of advanced age.
疾病的晚期;年迈的人