3 sentences

1. 秦老师是我们的班主任。

   Qín lǎo​shī shì wǒ​men de bān​zhǔ​rèn.

   Mr. Qin is our homeroom teacher.

   Source: Dong Chinese Dictionary

2. 诸老师是我们的班主任。

   Zhū lǎo​shī shì wǒ​men de bān​zhǔ​rèn.

   Mr. Zhu is our homeroom teacher.

   Source: Dong Chinese Dictionary

3. 我们的班主任对学生非常负责。

   wǒ​men de bān​zhǔ​rèn duì xué​sheng fēi​cháng fù​zé.

   Our homeroom teacher is very responsible for the students.

   Source: Dong Chinese Dictionary