【单选题】The most successful treatment described in the passage was a serum prepared from ______.
A.
the blood of patients who have been stung
B.
poison extracted from bees
C.
crushed bodies of bees
D.
a placebo and a crushed-body extract
【简答题】血浆与血清(plasma and serum)
【单选题】设函数【图片】, 则下列说法错误的是( )
【单选题】函数的垂直渐近线处是否一定对应其一个无穷间断点