while we were waiting to land ,an airhostess told us to keep calm and to get off the plane quietly as soon as it had touched down.while we were waiting to land ,an airhostess told us to keep calm and to get off the plane quietly as soon as it ___ ____同义句
问题描述：
while we were waiting to land ,an airhostess told us to keep calm and to get off the plane quietly as soon as it had touched down.
while we were waiting to land ,an airhostess told us to keep calm and to get off the plane quietly as soon as it ___ ____同义句
答
had landed