Definition. 1  Lactose intolerance refers to the inability of the body to digest lactose. 2  Lactose is the form of sugar present in milk. The enzyme lactase, which is normally produced by cells lining the small intestine, breaks down lactose into substances that can be absorbed into the bloodstream.
1 Tipping upon drop-off of your car is totally optional and is not done by the majority of drivers. Tip your valet when your car is returned to you from the parking lot.  A tip of $1 to $5 is the typical range, with $2-3 being most common.
Upon arriving at or leaving from the airport or train station, tip the standard porter rate of $1 per bag; more if your luggage is very heavy. Typically, a $1 tip for hailing a taxi is appropriate for doormen. However, you may want to tip more for special services, such as carrying your bags.