限时

shāng chǎng jīn tiān xiàn shí cù xiāo

商场今天限时促销。

Today the shopping mall is holding sales promotions for a limited time.

nǐ kě yǐ xuǎn zé zhī fù tǒng yī fèi yòng huò qǔ bù xiàn shí shàng wǎng

你可以选择支付统一费用获取不限时上网。

You can choose to pay a flat rate for unlimited internet access.