Explanation:

First statement is correct. One of the main benefits of eating roughage is that it helps to regulate your digestion. Insoluble fiber provides bulk in your intestines and helps to keep food moving through your digestive tract. Insoluble fiber absorbs water and swells into a gel that helps to keep bowel movements soft and easy to pass.
Though roughage is not a food, it is an important part of balanced diet, but it is important for the normal working of the digestive system. Dietary fibers provide bulk roughage to remove the undigested waste during defecation. The sources of roughage in our food are salad, vegetables & fruits with skin and high fiber contents.
Cabbage is one vegetable which provide us a lot of roughage. Corn cob & half – crushed, wheat also provide roughage to our body, along with other nutrients. All these food items have cellulose content which act as roughage. These fibrous material are good for digestion and helps in bowel movement.
However, roughage does not provide nourishment but still it performs useful functions:
1. It helps other foods pass easily through the digestive system and thus helps in- digestion.
2. Roughage contributes to the bulk of the faces and prevents constipation.
It also helps in retaining water.