--- There must be a dozen pens in this house but I can never find one when I nee
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--- There must be a dozen pens in this house but I can never find one when I need one.
--- Keep looking. _____ is sure to turn up.
A. One B. It C. That D. This
试题答案
A
解析:
此处用one表示泛指。keep looking继续找。