Read the excerpt from Chapter 5 of Wheels of Change. By the turn of the century, the bicycle's heyday was over and a new mechanical wonder promised to transport men and women faster and farther than ever before. Bicycle manufacturers retooled their factories to build them and bicycle repair shops installed gasoline tanks to service them. The era of the automobile had begun.

Which aspect of historical context does this excerpt most reflect?

a change in national politics
a change in society and its values
a development in technology
a development in world events

the answer is a . the absence of love

d) sarah's natural reaction to being accepted into college suggests that she has no other dreams.

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.