她要是注意到了那个标志的话，就会掉头回去了。
Had she noticed the sign, she would have turned back.
▼点击显示答案
had英 /hæd/|美 /hæd/
noticed英 /ˈnəʊtɪst/|美 /ˈnoʊtɪst/
would英 /wʊd/|美 /wʊd/
turned英 /tɜːnd/|美 /tərnd/
解释
Had she noticed 是 If she had noticed 的倒装形式；would have turned 中 would 表达在假设条件下必然发生的结果，have turned 构成完成式。整句表达对过去情况的虚拟假设——她实际上没有注意到标志，所以没有掉头。
Had she noticed the sign, she would have turned back.
Had she noticed 是 If she had noticed 的倒装形式；would have turned 中 would 表达在假设条件下必然发生的结果，have turned 构成完成式。整句表达对过去情况的虚拟假设——她实际上没有注意到标志，所以没有掉头。