This document provides information about PBL 4.1, including that it contains 6 items in section 1, 28 items in section 2, and 29 items in section 3. Sections 1 and 2 are to be completed individually, while section 3 involves group work. More details on PBL 4.1 can be found online at the provided URL.

1. PBL4.1
1.
2.

2. 3.
PBL 4.1
1. 6
2. 28
3. 29
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3.
- 1.
2.
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- http://kroohathaicho

3. n.wordpress.com
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- http://kroohathaicho
n.wordpress.com
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- http://kroohathaicho
n.wordpress.com
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4. 5
3-4
1-2