电力电容器的安装场所要求环境的最低温度和最高温度分别为()。
A.-40℃、+40℃
B.-40℃、+50℃
C.-20℃、+40℃
D.-20℃、+50℃
参考答案:A
若直线与圆的公共点的个数不小于1,则直线与圆的位置关系是______.
—You look upset.What's the matter?(2011·江苏)
—I had my proposal ________ again.
A.turned over
B.turned on
C.turned off
D.turned down