3 sentences

1. 那个小孩特别怕痒，一碰夹肢窝就大笑起来。

   nà​ge xiǎo​hái tè​bié pà yǎng, yī pèng gā zhī​wō jiù dà​xiào qi​lai.

   That child is very ticklish; he starts laughing as soon as you touch his armpits.

   Source: Dong Chinese Dictionary

2. 那个小孩特别怕痒，一碰到他的腋下就笑得停不下来。

   nà​gè xiǎo​hái tè​bié pà yǎng, yī pèng​dào tā de yè​xià jiù xiào de tíng bù xià​lai.

   That child is very ticklish; he can't stop laughing as soon as you touch his armpits.

   Source: Dong Chinese Dictionary

3. 我的后背被蚊子叮了一个包，抓挠了半天还是很痒。

   wǒ de hòu​bèi bèi wén​zi dīng le yī gè bāo, zhuā​nao le bàn​tiān hái​shi hěn yǎng.

   I have a mosquito bite on my back, and it's still very itchy even after scratching it for a long time.

   Source: Dong Chinese Dictionary