If you want the roses to remain fresh and new for a long period of time,then you will have to sprinkle fresh water on them and keep them away from dust and sunny places.

 How romantic of you!
The roses are drooping because 1) they are unable to take water and nutrients from their roots... And in the absence of those roots, to absorb water through the stem, and 2) They are being exposed to excessive heat.

So first, to preserve them as long as possible, keep them out of direct sources of heat or sunlight.

Second, as soon as you can after cutting them or bringing them from the market (or after delivery), stems should be cut at a 45 degree angle with a VERY sharp knife, which opens the avenues in the stem for absorbing water. If you cut them with a dull knife or use scissors, you will crush the tiny avenues within the stem whch allow them to continue to absorb water, so a sharp knife is important. It is better if you can manage to do this while the stems ends are submerged, but you can also do this on a cutting board/surface out of water, as well.

Third, prepare the vase of water that they will stand in. Water should be lukewarm - just very, very slightly above your body temperature--not cold, and certainly not warm. If you have 1/2 of an aspirin tablet, dissolve it in the water thouroughly in 1 about 1 quart of the water. (Some poeple claim 1/4 of a tablet of a tablet of "alka-seltzer" antacid works, as well, but I have never tried that.) I have great success using the 1/2 tablet of aspirin.

Unless the roses are very old and close to the end of their cut-life when purchased, they should last for 1-2 weeks in the vase.

Good luck!

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