即在阳光下，在灯下，在树阴下，穿衣、着装、冒雨等都要用in。

　　例：Don't read in dim light. 切勿在暗淡的灯光下看书。

　　They are reviewing their lessons in the bright light. 他们在明亮的灯光下复习功课。

　　They are sitting in the shade of a tree. 他们坐在树阴下乘凉。

　　a prisoner in irons 带着镣铐的囚犯

　　He went in the rain to meet me at the station. 他冒雨到车站去接我。

　　The poor dressed (clothed) in rags in old society. 旧社会穷人们衣衫褴褛．

　　以及：in the bright sunlight 在明亮的阳光下

　　a merchant in disguise 乔装的商人

　　the woman in white (black, red, yellow) 穿着白(黑、红、黄)色衣服的妇女

　　in uniform 穿着制服

　　in mourning 穿着丧服

　　in brown shoes 穿着棕色鞋

　　in his shirt sleeves 穿着衬衫

　　将来时态in...以后

　　例: They will come back in 10 days. 他们将10天以后回来。

　　I'll come round in a day or two. 我一两天就回来。

　　We'll be back in no time. 我们一会儿就回来。

　　Come and see me in two days' time. 两天后来看我。(从现在开始)

　　after... (从过去开始)

　　小处at大处in

　　例：Li and I arrived at Heishan county safe and sound, all is well. Don't worry. 李和我平安地到达黑山县，一切很好，勿念。

　　I live in a great city (big city), my sister lives at a small town while my parents live at a village. 我住在大城市，我姐姐住在一个小城镇，而我的父母则住在农村。

　　I'm in Liaoning, at Anshan. 我住在辽宁省鞍山市．

　　有形with无形by，语言 、单位、材料in

　　例：The workers are paving a road with stone. 工人们正用石子铺路。(有形)

　　The teacher is correcting the paper with a new pen. 这位教师正用一支新笔批改论文。(有形)

　　"Taking Tiger Mountain by Strategy" is a good opera. <<智取威虎山>>是-出好戏。(无形)