Racing the clock every day is such an exha
题型：单项选择题
问题：
Racing the clock every day is such an exhausting effort that when I actually have a few free moments, I tend to collapse.
A. fall down
B. fall ill
C. fall out
D. fall behind
Racing the clock every day is such an exhausting effort that when I actually have a few free moments, I tend to collapse.
A. fall down
B. fall ill
C. fall out
D. fall behind