口腔不良习惯占各类错畸形的()
A.29.4%
B.91.2%
C.90%
D.50%
E.25%
参考答案:E
沉淀IgG所用PEG6000浓度为()
A.3%~4%
B.6%~7%
C.8%~12%
D.12%~15%
E.25%
Peter ______ be really difficult at times even though he’s a nice person in general.
A.shall
B.should
C.can
D.must