has.
因为可以这样认为:
ten years ago 是修饰 your problems 的,所以对句子成分没有影响,可以不去看它.所以句子简化成:
what were your problems __ become mine.
又 were your problems 是修饰 what 的,所以对句子成分没有影响,拿掉后句子依然成立.所以句子再次简化成:
what __ become mine.
现在很清楚了,应该填 has 了.
has.
因为可以这样认为:
ten years ago 是修饰 your problems 的,所以对句子成分没有影响,可以不去看它.所以句子简化成:
what were your problems __ become mine.
又 were your problems 是修饰 what 的,所以对句子成分没有影响,拿掉后句子依然成立.所以句子再次简化成:
what __ become mine.
现在很清楚了,应该填 has 了.