QIHU [Qihoo 360 Technology Co] SC 13D/A: SCHEDULE 13D CUSIP No. 74734M109 Page 2 of
[SCHEDULE 13D CUSIP No. 74734M109 Page 2 of 15 1. Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only) SEQUOIA CAPITAL CHINA UR HOLDINGS LIMITED I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY) N/A 2. Check the Appropriate Box if a Member of a Group (See Instructions) ¨ x (a) 3. SEC Use Only 4. Source of]