布雷顿森林体系汇率浮动不超过（）
A.1%
B.2%
C.1.5%
D.3%
参考答案：A
解析：布雷顿森林体系规定汇率浮动不得超过1%。
_____ many times, but he still couldn't understand it. [ ]
A. Though he had been told
B. Having been told
C. Having told
D. He had been told
A．只在液体表面发生
B．只在液体的内部发生
C．在液体的表面和内部同时发生
D．在液体的表面和内部都不发生
