This research has been in progress since 1978 and has yielded many positive results.

这项研究自1978年以来一直在进行，并已取得了许多实际成果。

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This research has been in progress since 1978 and has yielded many positive results.

这项研究自1978年以来一直在进行，并已取得了许多实际成果。

youdao