我国军工企业自立项目、自筹资金、自主联合、自担风险研制的第一个军品项目是()
A、歼-7FS/MF
B、歼-7E
C、歼-7MG
D、歼-7PG
参考答案:A
试说出常见闸门埋件损坏情况有哪几种?
Only when he is seriously ill ______ in hospital.
A.he does stay
B.does he stay
C.he stays
D.stays he