Assimilation occurs when an immigrant
learns to speak the host country's official language
spreads his or her native culture to the host country
experiences little or no discrimination in the host country
dresses like others of his or her age group
moves into an ethnic enclave within the host country
i need it asap

learns to speak the host country's official language

Explanation:

The assimilation is a process through which a person integrates into a society that is different that the society of its origin. One of the first steps of assimilation is learning the language of the host country, as it is a must for communication and work. Further, the assimilation continues with the acceptance of the laws of the host nation, and gradually accepting its cultural traits over time. A perfect example of this is the United States, where there are people from all over the world, but they assimilate into one common culture of the host country.

b. arriving to class right before the test.