Unit 5 First aid教案
i want you to keep working unless i tell you to stop.
=i want you to keep working if i don’t tell you to stop.
如果我沒說讓你停，你就得繼續(xù)干。
注意：unless 不可用于假想的事情，因此當if...not引導非真實條件狀語從句時，一般不可改用unless。
高手過招
單項填空
①all the dishes in this menu, otherwise stated, will serve two to three people. （•全國ⅱ）
a. as b. if c. though d. unless
②don’t promise anything you are one hundred percent sure. （•浙江）
a. whether b. after c. how d. unless
③ you have tried it, you can’t imagine how pleasant it is. (•北京)
unless b. because c. although d. when
④we don’t keep winning games we keep playing well. (•浙江)
because b. unless c. when d. while
解析: ①選d。考查狀語從句的引導詞。句意為：在這份菜單上的所有菜，除非另外說明，會給兩到三個人食用。
②選d。句意為：除非你有完全的把握，否則不要做出承諾。unless除非。
③選a。句中unless意為“如果不”,可以與if...not互換。
④選b。unless意為“除非”,強調條件，符合句意。
10. john was studying in his room when he heard screaming.
約翰正在房里學習，突然聽到一聲尖叫。
此句型中when作并列連詞,相當于and then,意為“正當……時，突然”。
常用結構：
be doing...when... 正在做……突然……
had done...when... 剛做了……突然……