问题
选择题
MacDonald who had spent much of his time graduating from college backpacking round Europe,decided last year to settle down.
A．when
B．while
C．since
D．before
答案
答案：C
句意为“自大学毕业回来之后。MacDonald一直花费了他的大部分时间徒步环游欧洲，到去年才决定安下身来”。since表“自从……以来”之意。