加氢裂化的干气中的硫化氢含量应小于()PPm。
A、5
B、15
C、25
D、50
参考答案:D
To their great relief, the missing child returned home, ______, after an absence of two weeks.
A.felt tired and sound
B.tiring and soundly
C.feeling tired but soundly
D.tired but sound
There is going to _________an important meeting tomorrow. Please try _________late,
A.have; not to be
B.have; not be
C.be; not to be
D.be; not be