David has left a（n)______message to Lois which nobody can understand except her.A．clearB．i

I am sure David will be able to find the library because he has a pretty good ______ of di

We can infer from the speaker that______.A．IBM was his first jobB．he has left IBMC．he is a

He has left the book here______for you to read.A．on scheduleB．on purposeC．at randomD．at la

If only the message ______in time.A、arrivesB、is arrivingC、has arrivedD、had arrived

His sister left home in 1998, and _______since.A. has not been heard of B. has not bee

All the lights ______ before we left the office.A.has been turned offB.have turned offC.ha