[] [Wuxi Seamless Oil Pipe Co., Ltd. (as Borrower) and Bank of China Limited Wuxi Hi-tech Industrial Development Zone Sub-branch (as Credit Agent Bank) Supplemental Agreement to Comprehensive Credit and Loan Agreement between Wuxi Seamless Oil Pipe Co., Ltd. and Structured Bank Consortium in an Amount Equivalent to RMB3.5 Billion December 30, 2011 Wuxi Supplemental Agreement This supplemental agreement (hereinafter referred] [Certification by the Chief Executive Officer I, Longhua Piao, certify that: 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered] [Certification by the Chief Financial Officer I, Choon-Hoi Then, certify that: 2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered]