单站测试验证的重点是（）。

A.小区是否正常工作

B.下载速率是否满足要求

C.设备问题和工程安装问题

D.能否进行业务

The mother of a 9-month-old asks about adding new foods to his diet. The child is being breast-fed and takes formula and cereal when at the sitter’s. Which of the following would the nurse instruct the mother to do（）

A. Mix new foods with formula or breast milk.

B. Mix new foods with more familiar foods.

C. Offer new foods one at a time.

D. Offer new foods after giving formula or breast milk.