<p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span style="FONT-FAMILY: 宋体; mso-ascii-font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: 宋体; mso-fareast-theme-font: minor-fareast; mso-hansi-font-family: Calibri; mso-hansi-theme-font: minor-latin;">是范里安现代观点的一道练习题。</span></p><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none;"><span lang="EN-US" style="; FONT-FAMILY: "T10","sans-serif"; mso-bidi-font-family: T10; mso-font-kerning: 0pt;">Toby Talkalot subscribes to a local phone service that charges a fixed fee of $10 per month and allows him to place as many local phone calls as he likes without further charge. Let Good1 be an aggregate of commodities other than local phone use and let Good 2 be local phone use.(Measure Good </span><span lang="EN-US" style="; FONT-FAMILY: "T5","sans-serif"; mso-bidi-font-family: T5; mso-font-kerning: 0pt;">1 </span><span lang="EN-US" style="; FONT-FAMILY: "T10","sans-serif"; mso-bidi-font-family: T10; mso-font-kerning: 0pt;">on the horizontal axis and Good 2 on the vertical axis.) On Monday, Toby didn't use the telephone at all. From this we can conclude that the slope </span><span lang="EN-US" style="; FONT-FAMILY: "T9","sans-serif"; mso-bidi-font-family: T9; mso-font-kerning: 0pt;">m </span><span lang="EN-US" style="; FONT-FAMILY: "T10","sans-serif"; mso-bidi-font-family: T10; mso-font-kerning: 0pt;">of his indifference curve at the consumption bundle he chose on Monday was:<p></p></span></p><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none;"><span lang="EN-US" style="; FONT-FAMILY: "T6","sans-serif"; mso-bidi-font-family: T6; mso-font-kerning: 0pt;">(a) </span><span lang="EN-US" style="; FONT-FAMILY: "T5","sans-serif"; mso-bidi-font-family: T5; mso-font-kerning: 0pt;">positive.<p></p></span></p><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none;"><span lang="EN-US" style="; FONT-FAMILY: "T6","sans-serif"; mso-bidi-font-family: T6; mso-font-kerning: 0pt;">(b) </span><span lang="EN-US" style="; FONT-FAMILY: "T5","sans-serif"; mso-bidi-font-family: T5; mso-font-kerning: 0pt;">less than or equal to 0.<p></p></span></p><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none;"><span lang="EN-US" style="; FONT-FAMILY: "T6","sans-serif"; mso-bidi-font-family: T6; mso-font-kerning: 0pt;">(c) </span><span lang="EN-US" style="; FONT-FAMILY: "T5","sans-serif"; mso-bidi-font-family: T5; mso-font-kerning: 0pt;">0.<p></p></span></p><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none;"><span lang="EN-US" style="; FONT-FAMILY: "T6","sans-serif"; mso-bidi-font-family: T6; mso-font-kerning: 0pt;">(d) </span><span lang="EN-US" style="; FONT-FAMILY: "T5","sans-serif"; mso-bidi-font-family: T5; mso-font-kerning: 0pt;">greater than or equal to 0.<p></p></span></p><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; TEXT-ALIGN: left; mso-layout-grid-align: none;"><span lang="EN-US" style="; FONT-FAMILY: "T6","sans-serif"; mso-bidi-font-family: T6; mso-font-kerning: 0pt;">(e) </span><span lang="EN-US" style="; FONT-FAMILY: "T5","sans-serif"; mso-bidi-font-family: T5; mso-font-kerning: 0pt;">negative.<p></p></span></p><p class="MsoNormal" style="MARGIN: 0cm 0cm 0pt;"><span style="; FONT-FAMILY: 宋体; mso-ascii-font-family: T12; mso-fareast-font-family: 宋体; mso-fareast-theme-font: minor-fareast; mso-hansi-font-family: T12; mso-bidi-font-family: T12; mso-font-kerning: 0pt;">单选题，答案选</span><span lang="EN-US" style="; FONT-FAMILY: "T12","sans-serif"; mso-bidi-font-family: T12; mso-font-kerning: 0pt;">C</span><span style="; FONT-FAMILY: 宋体; mso-ascii-font-family: T12; mso-fareast-font-family: 宋体; mso-fareast-theme-font: minor-fareast; mso-hansi-font-family: T12; mso-bidi-font-family: T12; mso-font-kerning: 0pt;">，为什么？如果使用电话</span><span lang="EN-US" style="; FONT-FAMILY: "T12","sans-serif"; mso-bidi-font-family: T12; mso-font-kerning: 0pt;">0,</span><span style="; FONT-FAMILY: 宋体; mso-ascii-font-family: T12; mso-fareast-font-family: 宋体; mso-fareast-theme-font: minor-fareast; mso-hansi-font-family: T12; mso-bidi-font-family: T12; mso-font-kerning: 0pt;">就说明</span><span lang="EN-US" style="; FONT-FAMILY: "T12","sans-serif"; mso-bidi-font-family: T12; mso-font-kerning: 0pt;">MU2=0</span><span style="; FONT-FAMILY: 宋体; mso-ascii-font-family: T12; mso-fareast-font-family: 宋体; mso-fareast-theme-font: minor-fareast; mso-hansi-font-family: T12; mso-bidi-font-family: T12; mso-font-kerning: 0pt;">吧，而</span><span lang="EN-US" style="; FONT-FAMILY: "T12","sans-serif"; mso-bidi-font-family: T12; mso-font-kerning: 0pt;">MU1</span><span style="; FONT-FAMILY: 宋体; mso-ascii-font-family: T12; mso-fareast-font-family: 宋体; mso-fareast-theme-font: minor-fareast; mso-hansi-font-family: T12; mso-bidi-font-family: T12; mso-font-kerning: 0pt;">显然</span><span lang="EN-US" style="; FONT-FAMILY: "T12","sans-serif"; mso-bidi-font-family: T12; mso-font-kerning: 0pt;">>0,</span><span style="; FONT-FAMILY: 宋体; mso-ascii-font-family: T12; mso-fareast-font-family: 宋体; mso-fareast-theme-font: minor-fareast; mso-hansi-font-family: T12; mso-bidi-font-family: T12; mso-font-kerning: 0pt;">所以斜率</span><span lang="EN-US" style="; FONT-FAMILY: "T12","sans-serif"; mso-bidi-font-family: T12; mso-font-kerning: 0pt;">m</span><span style="; FONT-FAMILY: 宋体; mso-ascii-font-family: T12; mso-fareast-font-family: 宋体; mso-fareast-theme-font: minor-fareast; mso-hansi-font-family: T12; mso-bidi-font-family: T12; mso-font-kerning: 0pt;">该是负无穷吧？</span><span lang="EN-US" style=";"><p></p></span></p>