How many wheels are there on the trailer of an "18-wheeler" truck?

More Questions:

Which Canadian city is host to the Canadian International Autoshow?

Who composed the Christmas carol "Silent Night"?

How many strings do most guitars have?

The Arc de Triumphe is to Paris, as the Brandenburg Gate is to what other European capital city?

At what Seward Peninsula city does the Iditarod end?

What does a coleopterist study?

What is the temperature, at which dew forms, called?

What fruit comes in Hass and Florida variety?

The Michael Douglas film "A Perfect Murder" is a remake of what 1950s thriller?

What violinist performed the title character's solos in the film "Fiddler on the Roof"?

What is the profession of Jon Cryer's character on the TV show "Two and a Half Men"?

What was discovered in Sutter's Mill in California in 1848?

What island country announced its neutrality the day after the 1939 German invasion of Poland?

When was the Rosetta Stone found?

Who did Luther Vandross duet with in the 1992 single "Best Things In Life Are Free"?