可分泌IL-4、IL-5、IL-6和IL-10的细胞是
A.Th1细胞B.B细胞C.NK细胞D.CTLE.Th2细胞
参考答案:E
— Miss White has decided to explore in the forest by herself.
— She _____ ask her friends to if she dare go walking in the forest. [ ]
A. needn't
B. can't
C. would
D. should
石头蓄冷器和切换式换热器在冷段及热段的布置上各有什么特点?