What kind of athletic event(s) was/were held in the first thirteen Olympic Games

A．They are the world's most important athletic events and mark the friendship among people of the world.
B．They not only provide exciting sporting events but also make great contributions to world peace.
C．They allow people of the world to enjoy their most favorite athletic events and bring great economic benefit to the host country.
D．They offer the best sporting events and promote cooperation between countries.

A．the tusks of male elephants are usually large and heavy
B．tusks in good condition are in great demand, and may sell for as high as two thousand dollars or more
C．elephants are perhaps the only animals that are hunted for their teeth
D．an elephant uses its long, pointed tusks as tools for digging in the ground for food