when he heard the bell,he ran into the classroom ____?A.just now B.at once C.in a minute D.now为神马是B?不是A么?
问题描述：
when he heard the bell,he ran into the classroom ____?A.just now B.at once C.in a minute D.now
为神马是B?不是A么?
答
at once 立即
just now 刚才
句意：当他听见铃声，他立即跑进了教室。
答
just now意为刚才,是过去世的标志.
at once意为立即,与选题意思相符!