Does Kate have ___ at home?[ ]
A. stay
B. staying
C. to staying
D. to stay
答案：D
Supply chain is defined as the network including（）．
A．retailers&wholesalers
B．manufacturers
C．service providers
D．suppliers
推动教育研究前进的动力和源泉是（）。
A.理论
B.规律
C.问题
D.实践
