Check all that apply. Which of the following correctly defines a Boolean variable?

In python, len() is a type of :

The hyperpolarization phase of the action potential is primarily the result of the efflux (exit) of which ion?

We have the following Pandas dataframe df with two columns: school and student_size.    What would be the output data subset when we apply the following code: 

Alpha-gamma coactivation is essential to allow for an appropriate muscular response to stretch and tension. This activation causes (select the two that apply):

For vision, which of the following occur with the photoreceptor cells in the light (select the two that apply)?

For vision, which of the following occur within the photoreceptor cells in the dark (select the two that apply)?

T cells mature in (select the two that apply):

Isabella decided to buy the Honda CRV in white with Apple CarPlay, a wireless smartphone charger and a sunroof.  This is an example of which product level?  

Tupperware sells a wide range of products primarily focused on the kitchen and home directly to its users.  They are not for sale in stores like The Container Store, BrandSmart and other retailers.  This is an example of a(n) _____________________________________ .