1) Rita as well as her friends is present. 'Is' is used here because: When 'as well as', 'with', 'along with' are used to join two nouns in a sentence, the verb agrees this the noun mentioned first. Here, the noun mentioned first is 'Rita' and not 'friends'.
2) Two and two make four. 'Make' is used here because: two or more singular nouns joined by and requires a plural verb. Here ' make' is the plural one and not 'makes'.
