Placing the switch in the test position illuminates the indicator lights, and placing the switch in the dim position dims them. The above sentence means "将电门打到测试档位的时候，驾驶舱的指示灯关掉；将电门打到变暗档位的时候，驾驶舱的指示灯都变暗。
A.1
正确答案是B
Placing the switch in the test position illuminates the indicator lights, and placing the switch in the dim position dims them. The above sentence means "将电门打到测试档位的时候，驾驶舱的指示灯关掉；将电门打到变暗档位的时候，驾驶舱的指示灯都变暗。
A.1
正确答案是B