At what age do children have an understanding of between 20-30 words?

Which is NOT a basic message from the text with regard to puberty?

A) Children's reactions to their changing bodies depend on their environment. B) When children are undergoing puberty, it's crucial to provide nurturing schools. C) Communication about puberty needs improvement, especially for boys. D) Don't burden pre-teens by discussing puberty until the changes have occurred.

The only four ways that the base pairs of chemicals can pair up is _____, _____, _____, and _____

Fill in the blank with correct word