In contrast, California, home of Silicon Valley, recently proposed far more restrictive rules that would require human drivers be ready to take the wheel, and ban commercial use of self-driving technology.
2019年6月四級真題（第一套）閱讀 Section A
柯林斯高階英漢雙解學(xué)習(xí)詞典釋義
ADJ-GRADED
限制性的;約束性的
Something that is restrictive prevents people from doing what they want to do, or from moving freely.