! How does php submit multiple lists?

Urgent help! Php: how to submit multiple lists... As shown in, there are currently four single-choice lists and multiple-choice lists on the webpage. The purpose is that the user clicks the Submit button, obtains the selected options in the background, and then searches the database, finally, the corresponding search results are returned. & Nbsp; but now I do not know how to obtain the user's selection after clicking Submit! How does php submit multiple lists?
Tom posted for help... As shown in, there are currently four single-choice lists and multiple-choice lists on the webpage. The purpose is that the user clicks the Submit button, obtains the selected options in the background, and then searches the database, finally, the corresponding search results are returned.

However, I do not know how to obtain the user selection option after clicking Submit. That is to say, how can I write the Submit PHP code. It seems that escape characters are still involved in the middle. please help me!

Attachment: code snippets and web pages (the content in the form is mechanical feature. you can select feature to find the desired mechanical model)

1) This is a single-choice list

HTML code

     1" SQR. PANEL  0.95"X1.75" PANEL  2"X3" FLAT PACK PANEL  HAND HELD CALIBRATOR  EXP. PROOF CONDUIT  1.45"X2.55" PANEL  NEMA 4X2.6"X3.7" CONDUIT/WALL  1.6"X2" PANEL  AVIATION 1" DIAMETER  DINRAIL  3 1/2" BARREL PANEL  1/8 DIN PANEL  1/4 DIN PANEL  4" SWITCHBOARD PANEL  1.5"X2.9"X2" PANEL  6"X1" EDGEWISE PANEL  6"X1.75" EDGEWISE PANEL  6.6"X1.4" EDGEWISE PANEL  11.3"X1.4" EDGEWISE PANEL  7"X1.4" EDGEWISE PANEL  7.3"X2.8" EDGEWISE PANEL  6.3"X2.8 EDGE PANEL   5.7"X1.9" EDGE PANEL  5.7"X2.84" EDGE PANEL  NAKED PANEL/PCB MOUNT  6"X3.1" EDGE PANEL  6"X6"X3" SANITARY  VARIOUS SIZES & MOUNTING

2) This is a check list.

HTML code

  Outputs (Use ctrl+click to make multiple choices)     ANALOG 4-20mA/VDC  RELAYS  OPEN COLL. XTR  IRDA  4-20mA CALIBRATOR  WIRELESS ON REQUEST