问题
选择题
—How long have you been in this club?
—______ two years ago. [ ]
A. Since
B. For
C. At
D. Before
答案
答案：A
搜题请搜索小程序“爱下问搜题”
—How long have you been in this club?
—______ two years ago. [ ]
A. Since
B. For
C. At
D. Before
答案：A
关于碱金属元素的下列叙述中，错误的是（ ）
| A．碱金属元素原子最外层都只有1个电子 | B．随核电荷数递增，氢氧化物碱性增强 |
| C．随电子层数增加，原子半径增大，金属还原性增强 | |
| D．依Li、Na、K、Rb、Cs，单质熔沸点升高，密度增大 |
