如图所示，是一火警报警的一部分电路示意图。其中R2为热敏材料制成的传感器，该传感器的电阻随温度的升高而增大，电流表为值班室的显示器，a、b之间接报警器。当传感器R2所在处出现火情时，显示器的电流I、报警器两端的电压U的变化情况是（ ） A. I变小，U变小 B. I变大，U变小 C.I变小，U变大 D. I变大，U变大
----Now that you like the house with a garden, why not buy it? ----Well, I can’t afford _____ house at present. A. that expensive a B. a such expensive C. that an expensive D. a s
People in the United States honor their parents with two special days: Mother’s Day, on the second Sunday in May, and Father’s Day, on the third Sunday in June. These days are set aside to show lo
