One is the Arabic Numerals.
The Arabs produced the numbers we use, they named most of the stars that have names, plus they invented algebra. They also were the first to question and verify answers.
what is some of his achievements
Arabs are a type of people. Some people are safe and some are not. Being Arab does not have any effect on how safe a person may or may not be.
Sure. Some (or most) Muslim Arabs wear traditional clothing, but other Arabs - Christians, for example - wear very modern clothing.
Arab is an ethnicity, not a religion. Therefore there is no place of worship which is suitable for all Arabs. Most Arabs are Muslims and therefore pray in Mosques, but some Arabs are Christian and pray in Churches. Additionally, some Arabs are Jewish, Zoroastrian, Baha'i, Druze, and Yazidi, which leads to them praying in distinct houses of worship for those religions. Finally, some Arabs (although few are vocal about it) are Atheists and therefore do not worship at all.
causeways and files were some major achievements
the most impressive achievements were the pillars of Aksum
There are numerous Iraqi cultures and ethnic groups ranging from the Sunni Arabs to the Shiite Arabs, to the Marsh Arabs, to the Kurds, the Yezidi, the Yarsan, the Turcomans, the Assyrians, the Chaldeans, etc.
arabs wear almost no jewlery and if they did the jewelery must have been holy. or had some kind of value to them.
the most impressive achievements were the pillars of Aksum
some of the major egyptian achievements were paper, wine, and the first national monument
Yes, achievements is the plural form for the noun achievement.