在油品加氢过程中哪些物质对催化剂影响比较严重的是()。
A、金属
B、非金属
C、油品中存在的引起催化剂中毒的金属和非金属物质
D、油品中存在O、N、S化合物
参考答案:C
Many of his classmates came to his birthday party; , it was a great success to him. [ ]
A.at all
B.in all
C. above all
D. all in all
根据案例,可以测算出高先生从今年到退休时有( )年。
A.(A) 28
B.(B) 29
C.(C) 30
D.(D) 31