Which one is more important? 1-Length  2-Thickness  3- Efficiency?
552028
honestly #1 and #2 help but are not always the best. #3 is probably most preferred.
188295
2 inch is all you ever need unless you get a toy trailer -everyone I know with a pickup has always used 2 inch
705574
1) *more info?\n2) microscopy\n3) electron
965465
It is related to the length.
73259
I prefer motion. but if its too small then no matter the size of the ocean waves you had better compensate for the size.  I also must say that girth is much more important then length.
724445
Being a touch thick, what are key ratios?
794067
the bigger the ratio eg 6:1 is fast 2:1 is better for game fishing
774823
There are way more than three factors to consider.  The top three might be voltage, current and accessibility.  See the following link for more in-depth info.
690451
2 lines are better because most people use 2 lines. The computer uses 1 line because 2 lines would be too close together.
627256
that is good but what about thickness? :)
512848
Depends on your application.  Try both, and see which one suits you best.
732177
Density is important to :\n1. Transporter, because the vehicle has limitation on space (volume) and load. Thats why a transporter always has 2 tariffs. One is volumetric tariff and the other is weight tariff.\nWhen a transporter use only for example weight tariff then he will suffer from revenue if the customer load bulky but light weight material, that full load the vehicle but weigh a little.\n2. Packers, because they need to know size of pack to pack the material\n3. Engineers, scientist to calculate forces etc.\n4. Traders, to check purity of material.
660081
For a give weight of material, a flat material is stronger if you will consider a wide flanged beam to be a series of flat materials. \n\nIt really depends on the application. For beams, circular cross sections are not as efficient as the H shape of a wide flanged beam.\n\nFor columns a circular cross section can be more efficient depending on where the load is applied.\n\nThat is the reason structural engineers are employed to design structures. They can chose the correct configuration for each piece.
998220
thicker is better.  too long is just painful when it bumps the end of the cervix (plus all the nerves are in the first inch or so, so really long is just a waste).
254801
i would say a combination of 1 and 3.
898480
Makes no difference.\n\nThe only thing it affects is the price as 2*1gb would cost more.
513990
Question 1 used if three or more things to distinguish. Question 2 used if only 2 things to distinguish