3-2。What factors do affect the amount of the bacteria grows in packaged food？（ ） A: The type of the packaged food B: Temperature and time C: The structure of bacteria

Some products have been over-packaged just because of _____________________.( ) A: whole-sale and retailing B: the cost C: customers’ psychological need D: promotion

More and more consumers are snubbing packaged food’s sugar, salt and unpronounceable preservatives.

These have to be packaged up and to the post office. A: take B: taken C: took D: taking

中国大学MOOC: What does the author find after 30 days without packaged food?

He has just an email from Mr. Wang. A: judged B: overlooked C: packaged D: received

I have warned you not to do that __________. A: over and over B: over and over again C: again and over D: again and again over

求函数$y = {{1 + \root 3 \of {{x^2}} - \sqrt {2x} } \over {\sqrt x }}$的导数$y' = $( ) A: $ {1 \over 2}{x^{ - {3 \over 2}}} + {1 \over 6}{x^{ - {5 \over 6}}}$ B: $ - {1 \over 2}{x^{ - {3 \over 2}}} + {1 \over 6}{x^{ - {5 \over 6}}}$ C: ${1 \over 2}{x^{ - {3 \over 2}}} - {1 \over 6}{x^{ - {5 \over 6}}}$ D: ${1 \over 3}{x^{ - {3 \over 2}}} - {1 \over 6}{x^{ - {5 \over 6}}}$

中国大学MOOC: What should the author prepare before she went shopping in order to live a life without packaged food?

中国大学MOOC: The author dislikes the disposable culture in the modern society. (Backyard Agrarian’s 30 Days Without Packaged Food)