下列哪种传播途径引起的传染病大多见于儿童？（）。

A.经空气、飞沫传播；

B.经食物传播；

C.经水传播；

D.经虫媒传播；

E.日常生活接触传播。

What is the point the speaker is trying to make about technology development

A．A mature technology requires less innovation.

B．Technical evolution is close to maturation in certain fields.

C．New types of energy are expected to mature in the near future.

D．Nanomaterials or photonics and carbon nanotubes are environmentally friendly.