Misc: Particles of sand or stone mixed with cement to make concrete?

Questions

During one four-year period, Thomas Edison obtained ---------- patents, or one every five days.?

Medical researchers contend that no disease ever identified has been completely---------- .?

Every year, ---------- Americans injure themselves while trying out bizarre sexual positions.?

Every year, 11,000 Americans injure themselves while trying out ---------- sexual positions.?

In the U.S., there is, on average, ---------- sex change operations per day.?