原来如此。(Yuánlái rú cǐ.)I see; so that is what it is.

Explanation

“原来如此” 经常用作独立成分。指事情和自已以前想的不一样，在别人解释说明后或者经历了其他相关的事情后，后发现了事情的本来面目或真实情况。
“原来如此（yuánlái rú cǐ）” usually acts as a independent component. It refers to suddenly find the actual state of affairs or the truth after people explain or experience something relevant.

Words:

住院zhùyuàn:in hospital;

纳闷儿nàmènér:wonder.

Sentences

1、Jiă: Xiǎo Wáng de māma zuìjìn shēngbìng zhùyuàn le.
甲：小王的妈妈最近生病住院了。
A: Recently Xiaowang’s mom is in hospital.

Yǐ: Yuánlái rú cǐ, guàibudé tā kànqqǐlái méiyǒu jīngshén.
乙：原来如此，怪不得他看起来没有精神。
B: I see. No wonder he looks very weary.

2、Jiă: Tāliǎ zuìjìn zhèngzài nào máodùn.
甲：他俩最近正在闹矛盾。
A: They have problems with each other recently.

Yǐ:Wǒ hái zài nàmènr tāliǎ zěnme jiàn le miàn yě bù shuōhuà ne, yuánlái rú cǐ.
乙：我还在纳闷儿他俩怎么见了面也不说话呢，原来如此。
B: Now I see. I was wondering why they did not speak when met each other.

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