<p>Q1) Production delays (A:were notoriously) difficult obstacles to overcome until the company adopted new computer technology that works more effective than the old technology. </p>
<p>In this sentence, I thought A is wrong because you had to use Past participle when using word 'until'. </p>
<p>Answer is 'more effective'.</p>
<p>Q2) It appears that either Jane or Marek will be elected to be presidents of the student union.</p>
<p>A) to be presidents
B) as presidents
C) presidents
D) for president
E) president</p>
<p>Answer is E…</p>
<p>Q3) Teeming with hundreds of species of typical fish, the clear waters of the Caribbean Sea provide a paradise for scuba divers.</p>
<p>Answer is No Error, but i thought ‘clear’ must be ‘clean’ in that sentence…</p>