分子筛只吸附小于其孔径的分子,3A分子筛孔径约为0.3~0.33mm,故可以吸附()。
A.H2
B.O2
C.H2O
D.C2H4
E.C2H6
参考答案:A, B, C
每年何时为森林防火戒严期。
John applied for the post of Eliot's secretary. Does he __________ the necessary patience and ability
to do the job well?[ ]
A. perform
B. possess
C. observe
D. support