DP1: 句子完整性。register是及物动词,CD缺register后面的宾语,死;
DP2:指代。D中it指代the presence,而不是fever,导致后面的when it is there变成when the presence is there,illogical meaning,杀
DP3:把AB的one还原成a fever,再补完整,看句子:
The defective thermometers will sometimes fail to register a fever when it is present and indicate that there is a fever when it is not present.
vs
The defective thermometers will sometimes fail to register a fever when it is present and indicate that a fever is present when it is not present.
你选一个读起来意思明确的?