How does the author elaborate on the events that happened between 1955 and 1970?

The author provides facts about a and their effects. Research led the government to that cause air pollution. In response, many businesses were forced to

the answer is a.

explanation:

the clause "looking toward the south" modifies "a funnel cloud." it's not really the cloud that's "looking," but grammatically, that clause is modifying the cloud.

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.

when u add 2 plus 2 it equalls 4 bc 9 plus ten is zsdfsjnkdfjvnsdnf