[坎贝尔生物学 第745页] Campbell Biology 12th Edition
▼Figure 33.9 Anatomy of a planarian. Digestion is completed within the cells lining the gastrovascular cavity, which has many fine subbranches that provide an e
▼Figure 33.9 Anatomy of a planarian. Digestion is completed within the cells lining the gastrovascular cavity, which has many fine subbranches that provide an e