Because a comma is used to separate two meanings without using and
Answer:
<em>1) was working</em>
<em>2) is preparing</em>
<em>3) reads</em>
<em>4) completed</em>
<em>5) was doing</em>
<em>6) attended</em>
<em>7) had already finished</em>
<em>8) is completing</em>
<em>9) applying </em>
<em>10) is studying</em>
<em></em>
