优惠券有效期由即日至2007年7月31日止。

The coupon offer is valid until 31 July, 2007.

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一张有效期一个月的洗衣店优惠券(或者任何其它能减轻母亲烦恼的事)，如果家里已经有小孩，那就雇佣保姆吧。

A coupon to do the laundry (or whatever other chore your mom hates) for a month. If you have small children in the family, offer to babysit.

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类似的优惠券机会通常不会超过24个小时（尽管优惠券的有效期是几周或者几个月）。

The chance to snag one of these vouchers usually lasts no more than 24 hours (though merchants will honor them for weeks or months).

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