题目内容
（请给出正确答案）
Tom ________ the radio when I came in.
A、listened to
B、was listening to
C、listened
D、was listening
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更多“Tom ________ the radio when I …”相关的问题
A. Current
B. rad
C. /
模拟信号的数字处理系统，已知限带滤波器和平滑滤波器的截止角频率都为
选出应填入下面一段英语中______内的正确答案。
Rapid application development (RAD) systems purport to lighten the developer's(1)by making it easy to program an application with simple intuitive steps.
RAD tools(2)the developer everything needed to construct afully functional application quickly and easily. They make short work of modifying the developed with product to(3)changes after the program is finished. Applications developed with RAD tools are constructed as they are envisioned. As an application's real usefulness(4), the developer armed with a RAD tools should be able to(5)on new features with little fuss.
设控制系统结构图如图3-24所示，控制信号为r(t)=1(t)(rad)。试分别确定当Kh为1和0.1时，系统输出量的位置误差。
