I'm not familar with 2/3 but I hope this helps
1.
Mexico City, México
Guatemala City, Guatemala
San Salvador, El Salvador
Tegucigalpa, Honduras
Managua, Nicaragua
San José, Costa Rica
Panamá City, Panamá
4.
Caracas, Venezuela
Bogotá, Colombia
Quito, Ecuador
Lima, Peru
La Paz/Sucre (depending on what you've learned), Bolivia
Asunción, Paraguay
Santiago, Chile
Buenos Aires, Argentina
Montevideo, Uruguay
Tiene un resfriado. (She has a cold.)
Answer:
minimum speed to know if the whistle is working = 16.33m/s
Explanation:
Speed of sound, v= 343m/s
Hearing frequency of dog, f= 21kHz
Hearing Frequency of man, fₐ= 20kHz
Minimum travel speed, vₐ=?
Using the formula;
fₐ=(1-vₐ/v)f
20=(1-vₐ/343)21
(1-vₐ/343)=20/21
vₐ/343=1-0.9524
vₐ=0.0476*343
vₐ=16.33m/s
