Final answer:
The type of connective tissue containing mainly collagen in a watery matrix is cartilage.
Step-by-step explanation:
The kind of connective tissue that is mainly collagen in a watery matrix is cartilage. Cartilage is a supportive connective tissue with a large amount of the matrix, which is the most abundant feature in this tissue. The matrix consists of fibers largely made up of collagen and is produced by the cells called chondrocytes that reside in spaces within the tissue known as lacunae. While there are different types of cartilage, they all have in common the presence of collagen within a watery, gel-like matrix that provides structure and facilitates the tissue's slightly flexible nature. Contrarily, adipose tissue mainly serves to store energy and contains little extracellular matrix. Bone tissue, on the other hand, contains a rigid, mineralized matrix and is highly vascularized. Blood, classified as a fluid connective tissue, has a liquid plasma matrix and no fibers.