Question

2 which fact helps you conclude that an organism has an endoskeleton? a the organism is an invertebrate. b the organism has a hard shell. c the organism is a vertebrate. d the organism excretes chitin.

Explanation:

首先分析每个选项：A选项，无脊椎动物（invertebrate）通常具有外骨骼（exoskeleton）或无骨骼，而非内骨骼（endoskeleton）；B选项，硬壳通常是外骨骼的特征，比如贝类的壳，属于外骨骼范畴；C选项，脊椎动物（vertebrate）的骨骼位于体内，属于内骨骼（endoskeleton），这是脊椎动物的重要特征之一；D选项，排泄几丁质（chitin）常见于具有外骨骼的生物，如昆虫，几丁质是外骨骼的组成成分。所以判断一个生物有内骨骼的依据是它是脊椎动物。

Answer:

C. The organism is a vertebrate.