<span>Cell membranes are selectively permeable because it allows some things to enter or leave the cell while keeping other things outside or inside the cell.</span>
Answer
The answer and procedures of the exercise are attached in the following archives.
Step-by-step explanation:
You will find the procedures, formulas or necessary explanations in the archive attached below. If you have any question ask and I will aclare your doubts kindly.
Answer:
Doppler shift of the starlight
Explanation:
To predict the movement of a star, we compare the spectra of elements found in star (H, He Na etc.), first spectra which are obtained from star and second spectra from laboratory. If spectral lines of the spectra obtained from star, are shifting towards red end (called red shift) then star is going away from earth and if shifting is towards blue (called blue shift), then star is approaching the earth. This is Doppler's shift.
Pictures you asked, I hope you like the pictures
You haven't said how much power the stereo uses. It matters !
Whatever that number is, the maximum hours per month is
(3460) divided by (the # of watts the stereo uses when it's playing) .