There is a computer system _____he company is experiencing problems.

A.vacancy

B.desertion

C.emptiness

D.hollow

A.with start

B.with a start

C.starting

D.started

A.must learn

B.learns

C.learned

D.learn

A.die

B.death

C.dead

D.deadly

A. occurring

B. was occurring

C. was occurred

D. occurred

A. will

B. would

C. should

D. shall

A. potential

B. unknown

C. secret

D. unlimited

A. are

B. is

C. have been

D. has been

A.except

B.unless

C.except that

D.apart from

A. knows how

B. knows that

C. knew how

D. knew that