Compared with the walls of arteries, the walls of veins
a. are thicker.
c. lack valves.
b. are thinner.
d. have more resistance.

an obstruction

i think the answer is a, hope this is right, that would be my best guess.

u can delete ur account.

1. go on google and write

2 open this and click on your profile pic and if your profile is not appearing, then u have to log in.

3. when u click on your profile pic, there appears four options on the top.

4. click on the 1st option and scroll down and go at the bottom.

5. click on edit profile.

6. there appears a option 'prefernces' and at that option at the right side , 'edit' is written.

7. click on the edit option.

8. there is a option " i want to delete my account" and click on that.

hope this u

and ur welcm

: )

falling water hydro = water .. spectcular places these plants are