优质解答
不完全是 not really / quite / precisly (not +具有绝对的意思的形容词的副词）
原子序几乎是（但不完全是）和原子量的顺序相同.
The atomic numbers are nearly,(but not quite),the same as the order of the atomic weights.
完全不是 far from
不幸的是,实际情况完全不是这样.
Unfortunately,this is far from the real situation.
供参考
不完全是 not really / quite / precisly (not +具有绝对的意思的形容词的副词）
原子序几乎是（但不完全是）和原子量的顺序相同.
The atomic numbers are nearly,(but not quite),the same as the order of the atomic weights.
完全不是 far from
不幸的是,实际情况完全不是这样.
Unfortunately,this is far from the real situation.
供参考