第17题:[多选题]失去隔热性是指()。 A. 试件背火面的平均温升超过试件表面初始平均温度100℃ B. 试件背火面的平均温升超过试件表面初始平均温度140℃ C. 背火面任何一点的温升超过该点初始温度180 ℃ D. 背火面任何一点的温升超过该点初始温度200 ℃ E. 背火面任何一点的温升超过该点初始温度220℃ 参考答案:BC
第30题: [单项选择]The bird began to dance______. A. as soon as they saw him B. as soon as he had finished cleaning himself C. as soon as he settled down D. some time after they first saw them 参考答案:D 答案解析:[解析]该鸟首先cleaned himself 然后才开始dance。