Personification because it's saying the river knows as if it is a person or higher being.
Answer:
Adult smoking rates had been dropping for more than 30 years before teenagers began reducing their rates.
The correct answer is present progressive.
It means that there is some progression, that something is going on at the moment when this sentence is taking place. So, they are currently climbing to the top of the Aztec temple.
Present emphatic would be 'they do climb,' basic present would be 'they climb,' and present perfect would be 'they have climbed.'
<span>A. Once the cavity reaches the dentin, it must be cleaned and filled.
the other options are opinions</span>
