51.   In fact, using the Internet is so easy that many users have not taken formal courses, preferring to learn from friends or books.

52.   It would allow users to take handwritten notes on the device or create e-mails in handwriting, then link the data with laptop or desktop computers.

53.   The combination can also produce birth defects, so all users must take birth control during and after treatment.

54.   The report found that many drug users were taking multiple drugs, especially heroin users who were using cocaine at the same time, a potentially dangerous practice.

55.   Wyeth says that when the drugs were on the market, most users took them for three months or less.

56.   The researchers suggest that, in any case, contact-lens users take additional steps to clean their storage case by microwave or by boiling.

57.   Virtual reality allows the user to take part in simulated situations, such as flight and combat.