21．In ．19th -century Europe, ___ number of women used to wear corsets to achieve a body shape
A．the,/ B．the, a C．/,a D．/,the
22．—I'm sorry, I've left my credit card home, so I don't have enough money for the meal．
—Take it easy．_____
A．It's a piece of cake． B．It's my pleasure to pay you
C．It's my treat. D．It's at your expense．
