The answer could be "Intel." It is present as the processor in a laptop and is also advertised on t-shirts. Intel is often associated with high-performance technology, and having the highest mark in a class could symbolize having a superior intellect. The word "intel" is also a shortened version of "intelligence," further reinforcing the concept of being above average in intelligence.

Giải thích:

• "I am present in a laptop" - T có trong từ "laptop".
• "I am also a human's t-shirt" - T có trong từ "t-shirt".
• "I have the highest mark in class" - T là chữ đầu tiên của từ "top", nghĩa là cao nhất, đứng đầu.
• "I am usually described as something above" - T được sử dụng để chỉ các thứ ở trên, ví dụ như top, topmost, top-notch.