• 2022-06-17
    The inner layer of the exoskeleton (外骨骼) of an arthropod is called the ________. It contains chitin (几丁质), and its outer region is hardened. The outermost layer of the exoskeleton is waxy and impermeable to water.
    A: epicuticle (上表皮)
    B: procuticle (原表皮)
    C: hypodermis (真皮)
    D: basement membrane (基膜)