American’s  strengthening  economy caused an increase

American’s  strengthening  economy caused an increase in American demand for Japanese imports.
A、forcing
B、growing
C、slipping
D、weakening
【正确答案】：B
【题目解析】：strengthen 加强；增强；force促使； grow 生长；发展；slip滑过；weaken减少，使变弱；故选B。