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• v  undergo menstruation

• LIDDY: Let's hope that the key conferences aren't when she's menstruating or something, or just before she's going to menstruate.
• Some who have taken it for two years or more, then stopped because they wanted a baby, have failed to menstruate and ovulate, and therefore to conceive, for as long as 18 months.
• In the 1800s, social historians tell us, the average girl began to menstruate at 15; now the average age is 12.

• flow