【单选题】When you cross the street, you can never be ______ careful.
【单选题】You _____ cross the road when the traffic lights are red. It's dangerous. [ ]
【判断题】Python字符串支持与整数的乘法运算,表示序列重复,也就是字符串内容的重复,得到新字符串。
【单选题】You should be __________ when you cross the street.
【单选题】( )种子植物约5000种,数量居全国第七位
【单选题】When you cross the street, you can never be _______ careful.
【单选题】下列试剂不可以用于醛和酮鉴别的是( )。
【单选题】You _____ be careful when you cross here --- the traffic lights aren’t working.