1. flask-shaped gland unbranched ducts=SIMPLE ALVEOLAR GLAND
2. slender, straight gland unbranched ducts = SIMPLE TUBULAR GLAND
3. combination of gland shapes = TUBULAR ALVEOLAR
4.branched ducts=COMPOUND GLAND (salivary glands)
All of them are the exocrine glands (their product is secreted on the epithelial surface).