质疑GWD30-q20的答案，大家一起来讨论一下

GWD30-q20

Researchers have announced that the magnetic fields emitted by one manufacturer’s security surveillance system, of which type there are 200,000 worldwide, can interfere with pacemakers and that this interaction can bring on missed or irregular heartbeats, nausea, breathlessness, dizziness, and even fainting

1. of which type there are 200,000 worldwide, can interfere with pacemakers and that
2. of which, worldwide, there are 200,000 of that type, and which can interfere with pacemakers, and
3. of which type there are 200,000 worldwide, they can interfere with pacemakers and
4. 200,000 of which type exist worldwide, interfering with pacemakers, and
5. 200,000 of that type existing worldwide and can interfere with pacemakers, and

给的答案是D，其实我觉得应该是A

理由如下：1：如果选D，那么magnetic fields没有谓语，而A：of which type there are 200,000 worldwide, can interfere with pacemakers and that

                     can interfere是谓语

 2：题目中

Researchers have announced that the magnetic fields emitted by one manufacturer’s security surveillance system, of which type there are 200,000 worldwide, can interfere with pacemakers and that this interaction can bring on missed or irregular heartbeats, nausea, breathlessness, dizziness, and even fainting.

这里this interaction can bring 和the magnetic field ..................can interfere 平行

3：A：of which type there are 200,000 worldwide, can interfere with pacemakers and that

      这里  that可以使结构更加清楚：announced that ................and that

大家一起看看是不是这样：）