A:要在社会法制上起表率作用
B:着力建设社会信用机制,树立政府权威
C:以德治国比依法治国更重要
D:加强作风建设,严惩腐败
Do you always understand the instructions on a bottle of medicine? Here's one for John. John is twelve years old. He had a bad cold and coughed(咳嗽) day and night. He went to see a doctor and was given some cough medicine. Please read the following instructions and if you can understand them.
(Ⅰ)若直线l和曲线C有公共点,求倾斜角α的取值范围;
(Ⅱ)设B(x,y)为曲线C任意一点,求 3x+y 的取值范围.