Lesson One 2
Lesson Two 11
Lesson Three 21
Lesson Four 35
Lesson Five 47
Lesson Six 61
Lesson Seven 73
Lesson Eight 85
Lesson Nine 100
Lesson Ten 117
Lesson Eleven 133
Lesson Twelve 151
SUPPLEMENTARY READINGS 170
Ⅰ Why Read Faster? 170
Ⅱ Introduction 174
Ⅲ Filmless Cameras May Lead Next Boom in Photography 181
Ⅳ Interest Is Growing in Plastics That Can Conduct Electricity 185
Ⅴ The Age of the Sun 188
Ⅵ Big Numbers and Infinities 192
Ⅶ Too Many People? 200
Ⅷ Scientific Knowledge and the Young Scientist 206
Ⅸ Gettysburg Address 212
Ⅹ Dr.Bethune Speaks at the Opening of a New Army Hospital 214
APPENDIXES APPENDIX Ⅰ 220
1．Business Letters 220
2．Abstracts 224
3．Book Reviews 226
4．Instructions to Experiments 231
5．Laboratory Reports 238
6．Instruction Manual 250
APPENDIX Ⅱ 260
Irregular Verbs 260
APPENDIX Ⅲ 261
Vocabulary 261