what grammar problems and word choice problems do they have?
a. we cannot deliver the goods to you until friday.
b. Mandy is competent and a fast clerical officer.
c. The lastest catelogue is enclosed for your reference.
d. Please be advised that you should sigh the form before 1 March.
e. At the present time, our CEO is having a meeting with a very important client.
f. You will be happy to know our Central shop will be open until 12 midnight on Christmas Eve.