Answer:
I choose number 4) les because it sounds right
The correct demonstrative adjective for this sentences would be "este".
* Este niño en la foto es mi primo Francisco". Because "ESTE" refers to a singular male subject. If it would have been a girl, the correct option would have been "ESTA". For plurals we need to use "estos" and "esa" when it is a singular, female and we point the subject at a certain distance. "Esa es mi prima" --> That is my cousin (over there)
Answer:
a technical system is the conclusion of human work with tools or machines to obtain a finished product Give an example of the technical system at home
Explanation:
Hope that helps!