解放战争期间，中 * * 规定，用英文字母A表示电文机密程度，表示机密急电的是（）
A.A
B.AA
C.AAA
D.AAAA
参考答案：B
Before a tank is to be crude oil washed，the oxygen content in the tank must be measured at a position（）.
A.immediately above the level of the oil
B.at the top of the tank
C.in the vent riser
D.one meter from the deck
胃溃疡的疼痛规律为
A．疼痛—进食—疼痛B．疼痛—进食—缓解C．进食—疼痛—疼痛D．进食—疼痛—缓解E．无一定规律
