outermost shell造句怎么写

2、The outermost shell of the atmosphere, between the mesosphere and outer space, where temperatures increase steadily with altitude.

1、The outermost shell, important in eliciting the host's immune response, has been a focus of attention in vaccine development.

3、Elements in the first column all have one electron in their outermost shell. Those in the second column have two outer electrons, and so on.