英語語法----介詞Preposition（Prep.）
7）組成介詞短語 e.g.
by and by （不久） one by one（一個個地）
day by day（天天不斷地） step by step（一步步地）
side by side（肩并肩） little by little（逐漸地）
by chance （偶然，碰巧） by heart（默記下來）
by oneself（獨自地） by the way（順便提 / 問一下）
19.down 1）往下 e.g.
the boy fell down the stairs and broke his arm.
it was almost dark when he went down the hill.
2） up down
城市、北、河上游、近處 鄉村、南、河下游、遠處 e.g.
they were swimming up /down the river. i’ll go up to tianjin tomorrow.
do you see the man walking down the street? he’s my uncle.
(并非路面此高彼低，而是那個人離說話人而去。)
20.during 在……的期間 / 時候 e.g.
the story happened ~ the (american) civil war.
during the day, the light comes in through the window.
lao wang was in charge of the factory ~ the manager’s absence.
go over your lessons ~ your holidays.