检验批的抽样方案有( )。
A．免检
B．多样抽样方案
C．全数检验
D．随机抽样
E．分层抽样
参考答案：B,C,D
The US federal government has released 252 applications so far, ______ fields including education and health care.
A．covered
B．to cover
C．covering
D．having covering
简述干眼症的定义及诊断依据。
