机车信号的显示,应与线路上列车接近的地面信号机的显示方式相符。
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It was ____ that she couldn’t finish it by herself.
A. so difficult a work
B. such a difficult work
C. so difficult work
D. such difficult work
Most animals have little connection with animals of a different kind, ________ they hunt them for food.
A. if
B. while
C. unless
D. As
Hard working though he was, ________ there was never enough money to pay he bills.
A. /
B. and
C. but
D. Therefore
________ water is to fish, so air is to man.
As if
B. if
C. As
D. Although