It is difficult to write rules that tell exactly when we should apologize , and it is not difficult to learn how to do it 

(A) Difficult

(B) That

(C) When

(D) And

_________ the room, the man was no longer there.

A. Entering B. When we entered C. On entering D. Having entered

The clerks who are happy to wait for their customer will get promoted soon.

(A) Clerks

(B) Wait for

(C) Customer

(D) Get promoted

_________ anxious to please us, they told us all we wanted to know.

A. Be B. To be C. Being D. In being

_________at by everyone, he was disappointed.

A. Laughed B. Laugh C. Laughing D. In laugh

_________so much, the doll is still on the shelf.

A. Cost B. Costs C. To cost D. Costing

_________you to the job, he felt calm.

A. Appointed B. Appoint C. Having appointed D. To appoint

Practicing his speaking English everyday, his hope was to get a good job in a foreign company.

(A) His

(B) Everyday

(C) His hope

(D) To get

_________from what you say, you are innocent.

A. To judge B. Judging C. Judge D. To be judged

The lady _________in blue is her aunt.

A. dressed B. dressing C. is dressing D. in dress