_____ about Lucy, the teacher called her parents to find out why she was so often absent from class．
A．Concerning B．Considering C．Concerned D．Considered
—Do you mind if I smoke here?
—_____．I've got a bit of cold these days．
A．I'm afraid I do B．Of course not
C．No trouble at all D．Yes, just go ahead
He finds it hard to keep _____ with the change of society if he stops learning．
A．company B．time C．faith D．pace
If you don't go there, ______．
A．so will I B．neither do I C．so do I D．neither will I
She is already 18 years old, but she _____ as if she were still a little girl．
A．believes B．behaves
C．directs D．declares
The time has come ______ we can make extensive use of nuclear energy．
A．when B．which C．since D．while
