Một lô hàng gồm có 40 sản phẩn loại A và 60 sản phẩm loại B. Trong quá trình vận chuyển về kho bị mất một sản phẩm. Lấy ngẫu nhiên trong các sản phẩm còn lại 1 sản
phẩm. Tính xác suất để lấy được một sản phẩm loại A.

Awaiver of the requirement for documentation of informed consent may be granted when: the investigator has no convenient place to store signed consent forms separate from the research datathe only record linking the subject and the research is the consent document and the principal risk is a breach of confidentiality.potential subjects might find some of the research questions embarrassing, personal, or intrusivethe subjects are literate in their own language; however, they do not read, write, or speak english

You're doing research for a public essay on alternative medicine. which of the following sources has the most reliable information? a.a post on a social networking site about the undesired side-effects of different alternative medicinesb.a recent government report comparing the results of alternative and contemporary medicine for a specified diseasec.an anonymous article on a medical website that claims the success of alternative medicined.a 2003 study conducted by a medical research center about the effects of alternative medicine

Einar sees alexandra every day across the room in his history class but has never talked with her. einar likes the way alexandra looks, including the way she dresses and how she wears her hair. he's even more attracted to her apparent intelligence and the way she handles herself in class discussions and during interactions with the instructor. he'd like to know more about her, so he asks one of his friends about her. einar, using a passive strategy to gain information about her, is probably in the preinteraction awareness stage of any relationship that might develop between them. t/f