Questões Militares de Inglês - Infinitivo e gerúndio | Infinitive and gerund

According to the extract, what is the alternative that contains the right explanation about the gerund in bold type?

“Swimming is an amazing exercise. It’s healthy, fun, relaxing and a low-impact sport. I know this from personal experience. Last year while I was jogging I injured my left knee. I don’t go jogging anymore, now I’m considering joining a swimming competition.”

The gerund is:

Which option best completes the paragraph below?

Eat healthy

In today's fast-paced world, it is so easy ________ through a drive-through window to grab something to eat. It is also easy ______ into a gas station ______ a bag of chips, a soda, and some candy. However, ______ this is not the best choice for our bodies. Simply put - the more junk you put into your body, the worse you are going to feel. Try ______ your body with healthy food, drink plenty of water, and skip fast food lines as much as you can to feel healthy and happy.

(Abridged from http://www.teenadvice.about.com)

Fill in the blank with the correct response according to grammar rules:

I don’t mind _________ alone, but I prefer to travel with my friends.