选择题：典型的花由花萼、花冠、()、()。

林木结实量多的年份叫(),结实量少的年份叫()。

The company network is in the process of migrating the IP address scheme to use IPv6. Which of the following address types are associated with IPv6?()

Which command must be globally enabled on a Cisco router to support IPv6?()

目前应推广使用()效、()毒、低残毒,无公害的化学农药。

种子贮藏中最主要的病害是()。