自动降弓装置的特点是当降弓动作的同时自动切断机车主断路器，响应时间小于（）。
A、0.1S
B、0.2S
C、0.3S
D、0.4S
参考答案：B
Look at those ________. They are _______. [ ]
A. photoes; hers
B. photos; his
C. photo; her
D. photoes; mine
