【单选题】

The tango has probably traveled further and gone through more changes than almost (21) .African slaves brought the tango to Haiti andCuba in the 18th century; inCuba, the tango was influenced by the localCuban dance, (22) "the Havana". From there (23) took the tango inArgentina in the 19th century, (24) it was changed once again and became popular in the (25) . It was an erotic dance of working class people by this time. (26) made it difficult for middle-classEuropeans to accept.

(27) at the beginning of this century, the tango was refined, so that it (28) its erotic features. It was preformed in (29) casino ballrooms. The tango, in its sophisticatedEuropean (30) , became popular inEngland and in the USA、Once (31) , the tango became the rage in London and Paris. People began to (32) the Viennese waltz custom of dancing in restaurants between the (33) of a meal Proprietors (34) this, "for the pleasure of the customers and for the benefit of their digestion"!After "tango teas" (35) everywhere, even in private houses, LatinAmerican music was played for the tango, (36) more and more people owned gramphones.
The tango returned in (37) in a freer, more exotic form than (38) . Rudolph Valentino, the Holly-wood film star, began his (39) as a professional tango partner inAmerican tea-rooms. Valentino (40) immortalized the dance on film.
A．where
B．that
C．when
D．which