In this exercise, we are asked to point out the conjunction and to fill in the following sentence with the verb’s infinitive or present subjunctive: **(conseguir) No podemos visitar la selva tropical sin … una guía**.

The conjunction in this sentence is **sin** and since the subject doesn’t vary, the appropriate form of the verb to use is the infinitive **(conseguir)**.

No podemos visitar la selva tropical sin conseguir una guía.

In this exercise, we are asked to point out the conjunction and to fill in the following sentence with the verb’s infinitive or present subjunctive: **(poder) Debo salir de la cocina para que mamá … cocinar**.

The conjunction in this sentence is **para que** and since we are talking about the purpose of getting out of the kitchen, the appropriate form of the verb to use is the present subjunctive **(pueda)**.

Debo salir de la cocina para que mamá pueda cocinar.

In this exercise, we are asked to point out the conjunction and to fill in the following sentence with the verb’s infinitive or present subjunctive: **(dar) Esa foca no va a sobrevivir sin que nosotros le … comida**.

The conjunction in this sentence is **sin que** and since the subject varies, the appropriate form of the verb to use is the present subjunctive **(demos)**.

Esa foca no va a sobrevivir sin que nosotros le demos comida.

In this exercise, we are asked to point out the conjunction and to fill in the following sentence with the verb’s infinitive or present subjunctive: **(explicar) Un científico vino a la clase para … el efecto invernadero**.

The conjunction in this sentence is **para** and since the subject doesn’t vary, the appropriate form of the verb to use is the infinitive **(explicar)**.

Un científico vino a la clase para explicar el efecto invernadero.