A：使阴、阳离子结合成化合物的静电作用叫做离子键
B：含共价键的化合物不一定是共价化合物
C：化合物中只要含有离子键就一定属于离子化合物
D：金属元素与非金属元素相化合时一定形成离子键
Tom spent as little time as he could ____ (play) computer games.
受精的标志是（ ）
How ____ (care) you are! You've knocked the cup off the table again!
