Causes of headaches ___18___Even though the exact causes of a headache are not clear, most of them are caused by the widening of blood vessels (血管)combined with chemicals that are set free around them. Nerves send pain messages to your brain. There are many factors that can lead to...
[增分技法2] 因果关系 [典例] (2019·北京卷)Tina Stern 17.received rides from Wilson for all her four years in college, and the trips meant much more to her than just free 18.transportation. “It’s not just a ride;you’re not just sitting there in 19.awkward silence ...