6×6=____ 6×4=____ 6－3=____
6×2=____ 5×6=____ 4×6=____
6×5=____ 3×6=____ 6×4=____
如图为元素周期表中铈元素的信息，下列有关说法错误的是（ ）
下列离子组一定能大量共存的是（ ）
Not having __________ her daughter abroad for a long time, the mother was very worried.
