Answer:The si + present tense, present tense construction is used for things that happen
(regularly) when a condition is met. Note that the si in these sentences could
probably be replaced by cuando (when) with little or no difference in meaning.
Si llueve, no trabajamos - If it rains, we don't work.
No trabajamos si llueve - We don't work if it rains.
Si no quiero leer yo miro la televisión - If I don't want to read I watch TV.
Miro la televisión si no quiero leer - I watch TV if I don't want to read.
Si Present, Future
The si + present tense, future tense construction is used for events that will occur (in
the future) if the condition is met (in the present).
Si tengo tiempo, yo lo haré - If I have time, I will do it.
Yo lo haré si tengo tiempo - I will do it if I have time.
Si estudias, serás inteligente - If you study, you will be smart.
Serás inteligente si estudias - You will be smart if you study.
Si Present, Imperative
The si + present tense, imperative construction is used to give an order (in the
imperative) dependent on the condition being met (in the present).
Explanation:
2. Jorge irá a visitar monumentos en el centro 
4. Nosotros vamos vamos a nadar en el gimnasio