GWD 30-20

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

Answer is D, I dont understand. Mine is A.

数词 + of + Which 构成 非限定性定语从句

interfering做伴随目的状语从句

可能there be 结构表示"自然存在的", 所以错吧...

你说呢?

支持A

i prefer A

有没有人再来讨论一下,还是很迷茫

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
   
        A选项中是否会有两个that的并列的形式，然后后面跟上的
                   interaction是顺承interfere
        with pacemakers，这样不知是否会造成矛盾，
   然而D选项中确实会使一个announced that 后面没有谓语

vote for A

D的解释是说magnetic fields 和this interaction 并列

但是这犯了只关注语法不关注逻辑意思的错误

this interaction应该在之前的内容上有所体现才是