顺便问一下。(Shùnbiàn wèn yíxià.)By the way.

Explanation

“顺便问一下”通常作为插入语位于句首。说话人如果使用这句话，常常是在做某事或者询问某事时顺便咨询一下和这件事相关的其他信息。
“顺便问一下”(shùnbiàn wèn yíxià) usually acts as a parenthesis at the beginning of a sentence. If the speaker says it, he unusually want to ask some other information related to what he is doing or inquiring.
Words:

签收qiānshōu:sign;
快递kuàidì:express delivery.

Sentences

1、Jiă: Máfan qiānshōu nín de kuàidì.
甲：麻烦签收您的快递。
A: Please sign for your express delivery.

Yǐ: Xièxie. Shùnbiàn wèn yíxià, wǒ lìngwài yí gè kuàidì dàgài shénme shíhou néng sòngdao?
乙：谢谢。顺便问一下，我另外一个快递大概什么时候能送到？
B: Thank you. By the way, when will I receive my other one?

2、Jiă: Yín háng? Wǎng qián zǒu wǔbǎi mǐ jiù yǒu yí ge.
甲：银行？往前走500米就有一个。
A: The bank? There is one you go ahead for five hundred meters.

Yǐ: Xièxie. Shùnbiàn wèn yíxià, yínháng yìbān jǐ diǎn guānmén?
乙：谢谢。顺便问一下，银行一般几点关门？
B: Thank you. Buy the way, when does the bank close generally?