Answer:
1- Lo que necesita el país es más seguridad.
2- Lo mejor de mi banco es la atención al cliente.
3- Es impresionante lo rápido que ha sido el desarrollo financiero del país.
4- Lo único interesante de este proyecto es el presupuesto.
5- Es importante saber lo que (tú) tienes en la cuenta corriente.
6- Lo más peligroso en la bolsa de valores es la caída de precios.
Explanation:
Question 1, 2, 4 and 6 all have the verb "to be" in the simple present: "es". In English:
1- What this country needs <u>is</u> more security.
2- The best about my bank <u>is</u> the customer service.
4- The only interesting thing about this project <u>is</u> the budget.
6- The most dangerous thing about the stock market <u>is</u> the price drop.
Question 3 has the verb "to be" in present perfect, since it's something that started in the past and hasn't ended yet: "ha sido". In English the phrase means:
3- It's amazing how quickly the financial development of the country <u>has been.</u>
Question 5 has the verb "to have" in the simple present: "tienes". The pronoun "tú" is in parenthesis because it's redundant. In English the phrase means:
5- It's importan to know what you <u>have</u> in your checking account.
