课程目录：
├──Unit1
| ├──Unit1SectionA1a-2d
| | ├──U1A1b.mp3 589.31kb
| | ├──U1A2a.mp3 959.93kb
| | ├──U1A2d.mp3 429.31kb
| | └──Unit1SectionA1a-2d.pptx 3.68M
| ├──Unit1SectionAGrammarFocus-3c
| | └──Unit1SectionAGrammarFocus-3c.pptx 2.21M
| ├──Unit1SectionB1a-1f
| | ├──U1B1a.mp3 1.21M
| | ├──U1B1b.mp3 333.80kb
| | ├──U1B1d.mp3 1.31M
| | └──Unit1SectionB1a-1f.pptx 3.97M
| ├──Unit1SectionB2a-2c
| | ├──U1B2b.mp3 1.12M
| | └──Unit1SectionB2a-2c.pptx 4.67M
| └──Unit1SectionB3a-SelfCheck
| | └──Unit1SectionB3a-SelfCheck.pptx 2.71M
├──Unit2
| ├──Unit2SectionA1a-2d
| | ├──U2A1b.mp3 315.03kb
| | ├──U2A2a.mp3 595.84kb
| | ├──U2A2d.mp3 664.42kb
| | └──Unit2SectionA1a-2d.pptx 8.11M
| ├──Unit2SectionAGrammarFocus-3c
| | └──Unit2SectionAGrammarFocus-3c.pptx 5.39M
| ├──Unit2SectionB1a-1d
| | ├──U2B1b.mp3 412.99kb
| | └──Unit2SectionB1a-1d.pptx 5.56M
| ├──Unit2SectionB2a-2c
| | ├──U2B2b.mp3 614.62kb
| | └──Unit2SectionB2a-2c.pptx 3.60M
| └──Unit2SectionB3a-SelfCheck
| | └──Unit2SectionB3a-SelfCheck.pptx 4.64M
├──Unit3
| ├──Unit3SectionA1a-2d
| | ├──U3A1b.mp3 627.68kb
| | ├──U3A2a.mp3 384.82kb
| | ├──U3A2d.mp3 751.22kb
| | └──Unit3SectionA1a-2d.pptx 8.13M
| ├──Unit3SectionAGrammarFocus-3c
| | └──Unit3SectionAGrammarFocus-3c.pptx 3.92M
| ├──Unit3SectionB1a-1e
| | ├──U3B1c.mp3 697.48kb
| | ├──U3B1d.mp3 724.42kb
| | └──Unit3SectionB1a-1e.pptx 6.44M
| ├──Unit3SectionB2a-2c
| | ├──U3SB2b.mp3 1.25M
| | └──Unit3SectionB2a-2c.pptx 2.83M
| └──Unit3SectionB3a-SelfCheck
| | └──Unit3SectionB3a-SelfCheck.pptx 4.71M
├──Unit4
| ├──Unit4SectionA1a-2d
| | ├──U4A1b.mp3 437.07kb
| | ├──U4A2a.mp3 794.21kb
| | ├──U4A2d.mp3 562.78kb
| | └──Unit4SectionA1a-2d.pptx 15.05M
| ├──Unit4SectionAGrammarFocus-3c
| | └──Unit4SectionAGrammarFocus-3c.pptx 4.24M
| ├──Unit4SectionB1a-1e
| | ├──U4B1c.mp3 1.02M
| | └──Unit4SectionB1a-1e.pptx 5.51M
| ├──Unit4SectionB2a-2c
| | ├──U4B2b.mp3 705.23kb
| | └──Unit4SectionB2a-2c.pptx 4.18M
| └──Unit4SectionB3a-SelfCheck
| | └──Unit4SectionB3a-SelfCheck.pptx 3.80M
├──Unit5
| ├──Unit5SectionA1a-1c
| | ├──U5A1b.mp3 228.50kb
| | └──Unit5SectionA1a-1c.pptx 10.66M
| ├──Unit5SectionA2a-2d
| | ├──U5A2a.mp3 1.12M
| | ├──U5A2d.mp3 599.93kb
| | └──Unit5SectionA2a-2d.pptx 5.46M
| ├──Unit5SectionAGrammarFocus-3c
| | └──Unit5SectionAGrammarFocus-3c.pptx 3.81M
| ├──Unit5SectionB1a-1d
| | ├──U5B1b.mp3 760.74kb
| | ├──U5B1c.mp3 760.74kb
| | └──Unit5SectionB1a-1d.pptx 4.70M
| ├──Unit5SectionB2a-2c
| | ├──U5B2b.mp3 1.05M
| | └──Unit5SectionB2a-2c.pptx 3.71M
| └──Unit5SectionB3a-SelfCheck
| | └──Unit5SectionB3a-SelfCheck.pptx 3.07M
├──Unit6
| ├──Unit6SectionA1a-1c
| | ├──U6A1b.mp3 526.05kb
| | └──Unit6SectionA1a-1c.pptx 14.69M
| ├──Unit6SectionA2a-2d
| | ├──U6A2a.mp3 552.17kb
| | ├──U6A2d.mp3 682.78kb
| | └──Unit6SectionA2a-2d.pptx 3.67M
| ├──Unit6SectionAGrammarFocus-3c
| | └──Unit6SectionAGrammarFocus-3c.pptx 7.19M
| ├──Unit6SectionB1a-1e
| | ├──U6B1c.mp3 723.19kb
| | └──Unit6SectionB1a-1e.pptx 8.64M
| ├──Unit6SectionB2a-2c
| | ├──U6B2b.mp3 1.14M
| | └──Unit6SectionB2a-2c.pptx 6.37M
| └──Unit6SectionB3a-SelfCheck
| | └──Unit6SectionB3a-SelfCheck.pptx 3.22M
├──Unit7
| ├──Unit7SectionA1a-1c
| | ├──U7A1b.mp3 286.05kb
| | └──Unit7SectionA1a-1c.pptx 8.72M
| ├──Unit7SectionA2a-2e
| | ├──u7a2a.mp3 1.56M
| | ├──U7A2b.mp3 1.09M
| | ├──U7A2e.mp3 619.52kb
| | └──Unit7SectionA2a-2e.pptx 4.69M
| ├──Unit7SectionAGrammarfocus-3c
| | └──Unit7SectionAGrammarfocus-3c.pptx 5.59M
| ├──Unit7SectionB1a-1e
| | ├──u7b1a.mp3 2.78M
| | ├──U7B1c.mp3 733.80kb
| | ├──U7B1d.mp3 726.46kb
| | └──Unit7SectionB1a-1e.pptx 5.65M
| ├──Unit7SectionB2a-2c
| | ├──U7B2b.mp3 1.16M
| | └──Unit7SectionB2a-2c.pptx 3.51M
| └──Unit7SectionB3a-SelfCheck
| | └──Unit7SectionB3a-SelfCheck.pptx 3.80M
├──Unit8
| ├──Unit8SectionA1a-1c
| | ├──U8a1a.mp3 1.57M
| | ├──U8A1b.mp3 504.82kb
| | └──Unit8SectionA1a-1c.pptx 5.71M
| ├──Unit8SectionA2a-2e
| | ├──U8A2a.mp3 3.78M
| | ├──U8A2b.mp3 751.35kb
| | ├──U8A2e.mp3 546.87kb
| | └──Unit8SectionA2a-2e.pptx 4.07M
| ├──Unit8SectionAGrammarFocus-3c
| | └──Unit8SectionAGrammarFocus-3c.pptx 3.00M
| ├──Unit8SectionB1a-1d
| | ├──U8B1b.mp3 892.58kb
| | └──Unit8SectionB1a-1d.pptx 7.66M
| ├──Unit8SectionB2a-2c
| | ├──U8B2b.mp3 946.46kb
| | └──Unit8SectionB2a-2c.pptx 4.62M
| └──Unit8SectionB3a-SelfCheck
| | └──Unit8SectionB3a-SelfCheck.pptx 6.89M
└──Unit9
| ├──Unit9SectionA1a-1c
| | ├──U9A1b.mp3 601.97kb
| | └──Unit9SectionA1a-1c.pptx 8.06M
| ├──Unit9SectionA2a-2d
| | ├──U9A2a.mp3 216.66kb
| | ├──U9A2b.mp3 695.03kb
| | ├──U9A2d.mp3 700.74kb
| | └──Unit9SectionA2a-2d.pptx 4.42M
| ├──Unit9SectionAGrammarFocus-3c
| | └──Unit9SectionAGrammarFocus-3c.pptx 4.30M
| ├──Unit9SectionB1a-1d
| | ├──U9B1b.mp3 887.68kb
| | └──Unit9SectionB1a-1d.pptx 5.24M
| ├──Unit9SectionB2a-2c
| | ├──U9B2b.mp3 1.11M
| | └──Unit9SectionB2a-2c.pptx 2.91M
| └──Unit9SectionB3a-SelfCheck
| | └──Unit9SectionB3a-SelfCheck.pptx 2.41M
