181. through, across

through穿越空間，across在…上穿過 through the forest, across the desert

182. on the way, in the way

on the way在前往…的路上，in the way擋路 the chair is in the way.

183. above, on, over

above在上面，不接觸，on在上面，接觸，over在正上方 fly over the hill

184. until, not…until

until到…為止， not…until直到…才（常跟點(diǎn)動詞連用）i waited until 3:00. he didn't come until 3:00.

185. besides, except, except for

besides除了…還（包括在內(nèi)）except除了（不包括在內(nèi)），except for整體…除了某一點(diǎn)以外 the composition is good except for a few spelling mistakes.

186. weather, if

當(dāng)是否解時，只有在賓語從句中二者可以互換，其余都用whether，當(dāng)如果解時用if i don't know if/whether he will come. if he comes, i'll let you know.

187. and, or

and并且，or或者，否則，常用于否定句中 i don't like apples or bananas. hurry up and you'll catch the bus. hurry up or you'll miss the bus.

188. because, since, as, for

原因由強(qiáng)到弱為：because, since/as, for. 在句中的位置如下：1)…because… 2) since/as…, … 3) …, for… since i was ill, i didn't go.

189. when, as, while (表時間)

when從句動詞點(diǎn)動詞，持續(xù)性動詞均可，as重在表示動作同時發(fā)生，伴隨進(jìn)行，while從句動詞為持續(xù)性動詞 while i slept, a thief broke in.

190. the same…as, the same…that

the same…as和…一樣的（相似但不同一）， the same…that 同一物體 this is the same pen that i used yesterday. (同一支筆)

191. as well, as well as

as well也，常放于句末，和and連用表示既…又；as well as并列連詞，不但…而且… he is a professor, and a writer as well.

192. such…as, such…that

such…as像…樣的，such…that如此…以至于 he is not such a fool as he looks like. he is such a good student that all the teachers like him.

193. because, because of

because連詞，連接兩句話，because of介詞短語，后接詞或短語 he didn't go to school because of his illness.

194. in order that, in order to

表目的，in order that后接句子，in order to后接動詞原形 i got up early in order to catch the first bus. i got up early so that i could catch the first bus.

195. for example, such as

for example一般只列舉一個，such as列舉多個例子 i have been to a lot of american cities, such as new york, atlanta and chicago.