Which of the following are one-dimensional and have infinite length?

check all that apply.
a. angle
b. segment
c. plane
d. ray
e. point
f. line

Out of the choices, the entities with only one dimension and have infinite length are the line and ray. The line extends to both sides while the ray is restricted by an endpoint on one side but can extend infinitely to the other side. The answers are therefore letter D and F. 

Yes. there is a constant ratio of number of calories to gram of protein.12/3=24/4=32/8=44/11=4