Mark the odd one in each series.
salivary gland, thyroid gland, gastric gland, tear gland

Explanation

To determine the odd one out from the series: salivary gland, thyroid gland, gastric gland, and tear gland, we need to classify these glands based on their functions and characteristics.

### Step-by-Step Solution:

1. **Identify the Types of Glands**:
- Glands in the human body can be classified into two main categories: **endocrine glands** and **exocrine glands**.

2. **Define Exocrine Glands**:
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