السلام عليكم
لو سمتحم انا عايزه اعرف السؤال اللي ف الاختياري اختارتوا researching علي اي اساس

Research is work that involves studying something and trying to discover facts about it.
65 percent of the 1987 budget went for nuclear weapons research and production.

If you search for something or someone, you look carefully for them.
The Turkish security forces have started searching for the missing men...
Nonetheless there are signs that both sides may be searching for a compromise.
best wishes
Hamada Sabra

research can be used as a verb .itis the same meaning as do research