GWD-30-20 如果我的答案错了，就是题错了。

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

除了A有谓语，哪项还有原文的谓语啊~~~ 答案居然是D，搞什么啊~~

我也选了A

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

 only D or E is possible correct because of usage of "200,000 of which". 

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

= researcher have announced that the magnetic fields and this interaction can bring.....

a肯定不对，最后的that

b肯定不对，of which there are

c肯定不对，of which there are

e肯定不对，of that

也就只有d最顺眼了。考试嘛，作对为止就可以了，别叫真

显然不是并列；后面一个是承接前面从句中所说的interference....故不用and that...

vote for A

Not that good question, however, I'll choose A

D has no verb in the clause and it will be awkward to put "system and interaction" together playing role as subject.