How to put two sections next to each other in a form

I am having trouble getting two sections to be next to each other on every line of the form we are working on. I can put a "first name" and "last name" section next to a drop down on one line, but can only fit one of the two on the next. After that single section, however, I can put both on a line. How can we get both the first name" and "last name" section next to a drop down on every line? Please see the link I have attached of the form for better understanding! 

Its possible. I cloned your form and modified it:

https://form.jotform.com/73447006546962

First you need to increase the width of your form to 800 pixels

Open the form designer (paint roller icon). And on the styles tab you will see the form width option:

Next you need to position your fields. 

You must use "shrink" for every field.

And "move to a new line" for the first field of each line.

Please see this short guide:

Form-Field-Positioning