当P含量大于()时,钢将完全变成脆性。
A.0.1%
B.0.2%
C.0.3%
D.0.4%
参考答案:C
斗轮机的回转半径为()。
A.30米
B.35米
C.50米
D.15米
—I phoned you at 7 yesterday evening but nobody answered.
— Oh, I ______ my dog in the park then.
A.walked
B.was walking
C.had walked
D.would walk