【单选题】

Rhythm and blues, or R&B, is a (26) of music that came out of the jazz, blues and gospel music that was being (27) byAfricanAmericans (28) the l930s and l940s. Over the years, the term has commonly been used to describe (29) popular music this community was played at the time. This more upbeat, exciting type of music caught on (30) a big way, and for the first time,AfricanAmericans (31) their own style of commercial musiC、

In the late 1930s, many big bands broke up (32) smaller units and formed "jump blues" bands (33) played loud music with a strong dance beat, quickly (34) popular in the dance halls at the time.
Early R&B、 (35) were those ofCountBasie, Louis Jordan and Lionel Hampton.Basie had a hit in 1937 with One O’clock Jump, (36) Jordan had a string of hits from the late l930s through the l940s.By the mid 1940s, R. M.Blues by Roy Milton and The Honeydripper by Joe Liggin each (37) one million copies.
The new music style (38) to evolve and was gaining (39) rapidly. InAnnapolis, more than 50,000 people (40) up to a concert with seating for 8,000. There was a traffic (41) for seven hours.
Rhythm and blues has come a long way (42) AmericanAfrican musicians of the mid 20th century developed their own style of (43) music based on some more conservative styles at the time. R&B、had huge success in the 1950s and l960s before making an even (44) comeback as contemporary R&B、 (45) the l980s on.
A、wheneverB、whicheverC、whateverD、however