A mountain bike OA
Has narrow tires for speed
OB.
Has a wider tire with thicker tread
OC. Stays in place while you ride
OD
Has two seats

answer: our bodies are made up of mostly water, we rely on it to regulate our body funtions.

b

explanation:

because i can

exposure to hazardous carcinogens and toxic substances can cause breathing problems, such as copd and various types of cancer. it also increases the risk of heart attacks and strokes and has serious (but no less unattractive) side effects, such as aging, yellow teeth, a terrible smell and damage to the vocal cords.