Mecca and Madina
There is no holy river for Muslims or for Islam religion.
Most of the holy cities of Islam are situated in Saudi Arabia. Anyhow, many other countries like Iraq, Pakistan and India also have holy cities for the Muslims.
The most sacred two cities of Islam are Makka and Madina Munawara.
Arabs are an ethnicity, so they do not have any holy cities per se. However, as over 90% of Arabs are Muslims, it would be safe to say that Mecca, Medina, and Jerusalem, the three most holy cities in Islam, are holy to most Arabs.
Islam's Most important religion figure is Prophet Muhammad (peace be upon him). Prophet Muhammad is God messenger and prophet who received God revelation of Quran, Islam religion holy book, through the angel Gabriel (Jibril).
Islam is a religion - therefore the answer is Islam.
Islam is a universal religion. Its followers use different languages. However, the holy Qur'an, most sacred book of the Muslims, was revealed in Arabic.
There is no Malay holy book as such. It seems that race and religion have been confused. Most Malays are Muslims. They embrace Islam and the holy book of Islam is the quran/qoran/koran. Malays can be non-Muslims too. Malay is a race, not a religion. In Malaysia, there are Indian Muslims and Chinese Muslims. Hope it helped.
Mecca is a city in Saudi Arabia that is considered the holiest city in Islam. It is the birthplace of the Prophet Muhammad, and the site of the Kaaba, the most sacred site in Islam. Mecca is central to the Islamic religion and is a destination for the Hajj pilgrimage.
No. Islam is the religion of which a Muslim is a follower. The Koran is the holy book of Islam and it is written in the Arabic language.Arabic is a holy language in Islam and most of Islamic Theological Scholarship is written in Arabic. However, most Muslims do not speak Arabic and instead speak whatever languages prevail in their countries of residence, so there is no universal "Islamic Language".
Islam is a religion. Followers of Islam are currently around one fourth of world population. refer to related question for more information. In Saudi Arabia there are two holy cities: Mecca (or Makkah) and Medina.
The more the specific religion followers the more will be the converts from this religion to Islam. Accordingly, most converts to Islam are from Christian religion. Some think that most converts to Islam are from people who had no previous convictions or beliefs. Refer to links below