请找出定语从句,并理解其用法及含义。 1. The Centre’s Shop with Your Doc’s program sends doctors to the grocery store to meet with any patients who sign up for the service. (CET-4, 2018. 12, Reading Comprehension, Section B) 2 ....they ‘re also realistic about the risks and dangers that lie ahead... (CET-4, 2014. 12, Reading Comprehension, Section C, Passage One) 3. Of the produce that does appear in the supermarket, commonly used sales promotions frequently encourage customers to purchase excessive quantities which...inevitably generate wastage in the home. (CET-6, 2013. 12, Reading Comprehension) 4. This occurs at a time when other nations have made significant gains in their own research capabilities. (CET-4, 2014. 12, Reading Comprehension, Section C, Passage One) 5. Even people whose data are less popular can benefit. (CET-4, 2014. 12, Reading Comprehension, Section C, Passage One)