昨天上午10点正在下大雨. It ______ ______ ______ at ten o'clock yesterday morning.

昨天上午10点正在下大雨. It ______ ______ ______ at ten o'clock yesterday morning.
昨天上午10点正在下大雨. It ______ ______ ______ at ten o'clock yesterday morning.

昨天上午10点正在下大雨. It ______ ______ ______ at ten o'clock yesterday morning.
答案：填was raining heavily
解析：时态是过去进行时,而且形容下雨大用heavily
即 It was raining heavily at ten o'clock yesterday.
有不明白的请继续追问,

应该填写
was just raining
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