Do you know if he ________ come tomorrow? [ ]
A. will
B. would
C. is
D. isn't
答案:A
They _____ England and they will be back next week.
A.have gone to
B.have been to
C.have gone in
D.has been on
防爆阻火器具有良好的“三防”性能,它在瓦斯压力为()下,发生瓦斯爆炸时不传爆。
A.0.11MPa
B.0.17MPa
C.0.24MPa
D.1MPa