Which of these is a reliable type of Internet source? wiki sites
personal blogs
commercial sites
government sites

D, Government Sites

Explanation:

Government sites will always have correct information as they are run by the government. Wiki sites like Wikipedia allow users to change information on the page, personal blogs have no obligation to be correct, and may be biased, finally commercial sites may be biased or try to give the user incorrect information to interest them in their product.

the present continuous is a verb tense which is mainly used to indicates that an action is in progress at the moment of speaking.  

it is formed using: person + verb to be (am/is/are) +verb + - ing form  

example: i am studying at this moment .

in addition, the present continuous is also used in order to express things that will or will not happen in the near future.

example: i am having dinner with some friends tonight.

the speaker sometimes   uses it   to express that an action is repeated and it causes irritation on the part of the speaker

example: my sister is constantly complaining about everything.