3 sentences

1. 他在公园里拉二胡。

   tā zài gōng​yuán lǐ lā èr​hú.

   He is playing the erhu in the park.

   Source: Dong Chinese Dictionary

2. 制作二胡弓弦需要用到优质的白马尾。

   zhì​zuò èr​hú gōng​xián xū​yào yòng​dào yōu​zhì de bái mǎ​wěi.

   Making Erhu bowstrings requires high-quality white horsehair.

   Source: Dong Chinese Dictionary

3. 这把二胡的弓是用马尾做的，音色非常优美。

   zhè bǎ èr​hú de gōng shì yòng mǎ​wěi zuò de, yīn​sè fēi​cháng yōu​měi.

   The bow of this erhu is made of horsehair, and its tone is very beautiful.

   Source: Dong Chinese Dictionary