英語六級-聽力口語關鍵句21. You see, I still have this pain in my back

21. You see, I still have this pain in my back; this medicine the doctor gave me was supposed to make me feel better by now.

點睛　

被動語態(tài)表示主動含義的用法在英語里很常見，但卻與我們中國人的思維習慣相去甚遠，考生需多加練習。分號后句子的意思是“醫(yī)生給我開的藥現(xiàn)在應該可以使我感覺好些了（意為說話人的癥狀現(xiàn)在未見好轉(zhuǎn)）”。

考點歸納　

be supposed to的用法如下：
當be supposed to的主語是sb.時，意為“應該；被期望”，可以用來表示勸告、建議、義務、責任等，相當于情態(tài)動詞should。如：
Teachers are supposed to treat all students alike. 老師應該對所有學生一視同仁。
當be supposed to的主語是sth.時，意為“本應，本該”，用于表示“某事本應該發(fā)生而沒有發(fā)生”。如：
The train was supposed to arrive an hour ago. 火車本應在一小時之前到達。
當be supposed to后接“have＋過去分詞”時，表示“本應該做某事而沒做”。如：
You are supposed to have handed in your homework by now. 到現(xiàn)在你應該已經(jīng)把作業(yè)交上來了。
be supposed to的否定結(jié)構(gòu)為be not supposed to，常用于口語中，意為“不被許可；不應當”。如：
She was not supposed to be angry about that. 她本不該為那件事而生氣的。