【单选题】听力原文:(A) She is peering through the microscope. (B) She is wearing the eyewear. (C) She is taking off her gloves. (D) She is labeling a sample.
【简答题】讨轮并计算广义二重积分 其中D={(x,y)|xy≥1,x≥1}
【简答题】设 计算二重积分 其中 D={(x,y)|x 2 +y 2 ≥2x}.
【简答题】计算二重积分 其中D是曲线 和直线y=-x围成的区域
【单选题】吸氧时,氧流量为3L/min,吸氧浓度为( )。
【单选题】高强度钢内部晶粒变大融合后,强度会( )。
【单选题】When she had looked through the book briefly, she handed it back to me.
A.
She handed the book to me
B.
She looked through the book