A recent study has found that amoxicillin, long a standard treatment for ear infections, is about as effective as newer, more expensive antibiotics and causes fewer side effects.
long a standard treatment ----long ,for a long time 可以作定语
as newer,more expensive -----介词+名词,+名词
说说个人的观点,
But last year the UK government abandoned plans 【to limit the tax relief given to those who donate to charity】 after an outcry from universities, the arts sector and charities. It had said it wanted to clamp down on tax avoiders.
这里的括号部分都是修饰plans的,after后面的部分修饰了abandoned这个动词
我个人觉得一般介词短语部分一般很少修饰“修饰成分,类似【to..】这部分”,都是直奔主干部分
An online campaign has been started by police officers around the country offering to work for GMP on the day of the dead officers' funerals to allow all their GMP colleagues to attend the services.