昆虫体壁的结构由外及里可分为皮细胞层、表皮层和底膜。

单项选择题绝大多数昆虫的后翅为膜翅。

单项选择题'An organisation is a social arrangement which pursues collective............................................. , which controls its own performance and which has a boundary separating it from its environment.' Which of the following words best completes this sentence?