user: What is the Maareech Advanced Torpedo Defence System (ATDS)?

assistant: The Maareech Advanced Torpedo Defence System (ATDS is a torpedo detection and countermeasure system used by the Indian Navy.

user: How can I learn how to ski?

assistant: While there are many different ways to learn how to ski, here are some of the more common ones:

1. Take a professional lesson. These are typically offered as half-day or full-day, and either as a private lesson or in a group of typically up to eight people.

2. Have a friend teach you. This is a more cost-conscious way, however, ensure that your friend knows how to properly teach.

3. Teach yourself. Utilize video tutorials found on various sites and get out there and try it.

Remember that skiing, while fun, is still an activity that could cause harm, so be sure to always wear a properly fitting helmet.

user: What is Twice's debut album?

assistant: Twice is a South Korean girl group that was formed under a television program called Sixteen on October 20, 2015. The group debuted with an EP called "The Story Begins." The group then went on to make their debut in Japan under Warner Music Japan on June 28, 2017 with a compilation album named "#Twice".