Three-month-old zoey looks up at her mother and smiles. researchers call this type of smiling:

According to subpart d, research with children may be eligible for exemption when: the children will be asked to complete a surveythe research involves the use of educational teststhe children will be interviewed by the researcher.the research with children will involve participant observation with researcher interaction.

What’s the reason for not digging up aztec ruins in modern mexico city

Is it true the ancient egyptians created a calendar that had 10 days in a week