low, lower, a lower; that, which, what The scientists began investigating the link between IQ and vegetarianism because people with higher intelligence have____ risk of heart disease,____ has long puzzled doctors.
low, lower, a lower; that, which, what The scientists began investigating the link between IQ and vegetarianism because people with higher intelligence have____ risk of heart disease,____ has long puzzled doctors. 【正确答案】：a lower; which
