While the effect of cows milk harvested at different time has not been tested on humans up to now, taking melatonin drugs has been suggested to those who are struggling to fall asleep at night.请问这里的time 为什么不用复数?
He spoke so fast that I could not follow.It was so easy a question that every one of us could answer it.Much to his surprise,none of them could tell the difference between them.这些个例句中的could是表示过去的能力吗?她们能否用 was able to来替代?
...base access, is problematical at best.这句话,that引导了主语从句,considering作为非谓语动词用现在分词我能理解,可是在张满胜老师的著作中解释说,considering后面的shrinking U.S. defense budgets and diminishing overseas base access是并列...