主要由Th2细胞产生的促进IgE形成的细胞因子是（）
A.IL-1
B.IL-5
C.IL-4
D.IL-8
E.IL-12
参考答案：C
If the economy is just coming out of a recession, which one of the following would represent a typical sequence of phases in the business cycle（）
A. Expansion, business peak, contraction, recession.
B. Expansion, business peak, recession, contraction.
C. Depression, expansion, business peak, contraction.
电缆沟施放电缆不可能造成电缆损坏。（）
