题目：
根据句意和汉语注释，写出单词的正确形式。
小题1:As we know, oil always __________ (漂浮) on water.
小题2:He __________ (点头) to me in greeting when I entered the room.
小题3:We are very __________ (自豪) that a pupil from our school has won the prize.
小题4:They all hurried __________ (往楼上) to see what was going on.
小题5:There was __________ (沉默) for a moment and then someone made a useful suggestion.
答案：
小题1:floats
小题2:nodded
小题3:proud
小题4:upstairs
小题5:silence
小题1:考查时态。根据always可知，用一般现在时。故填floats。
小题2:考查时态。根据entered可知，用一般过去时。故填nodded。
小题3:考查固定句型。be proud of/that从句，“以......而自豪”。故填proud。
小题4:考查副词。hurry to“匆忙赶往”，upstairs“楼上”。故填upstairs。
小题5:考查there be句型。there was后跟名词。故填silence。
