17 ) recibió
18 ) prepara
19) comemos
20 ) pone
Tú casa es grande.

The difference between "tú" and "usted" depends on the formality. "Tú" is used <u>when talking to friends or relatives (informal)</u> while "usted" is used <u>when talking to older people or a person of high social rank (formal)</u>.
In this case we want to write the <u>informal</u> form of "tú", so we use "tú". Also, when dealing with <u>permanent states</u>, the verb "ser" (to be) is used.
They are the same. 1 Panamanian Balboa is equal in value to the US dollar. This changed throughout history but never too much. You can however still use regular US dollars to pay for things in Panama and the merchants won't bother you about it. This is because of historical events and colonization and freedom of panama and it's relations with the US.
Cokroach = cucaracha (Mexico and Spain at least).
Hope it helped,
BioTeacher101