Writing help!

<p>ok so i had trouble with these two questions on a practice test. The parentheses means that portion was underlined.</p>

<pre><code> In 1988 a Soviet icebreaking ship (helped free) three gray whales that (had become trapped) in the Artic ice after they (had swam) into the coastal waters of Alaska (to feed).
</code></pre>

<p>The Bactrian camel (is) well adapted to the extreme climate of its native Mongolia, (having) thick fur and underwool that (keeps) it warm in winter (and also) insulate against summer heat.</p>

<p>Can someone please explain to me the error in each of these sentences? Thank you.</p>

<p>
[quote]
In 1988 a Soviet icebreaking ship (helped free) three gray whales that (had become trapped) in the Artic ice after they (had swam) into the coastal waters of Alaska (to feed).

[/quote]
</p>

<p>The past participle of "swim" is "swum." I swim today; I swam yesterday; I had swum before I swam.</p>

<p>
[quote]
The Bactrian camel (is) well adapted to the extreme climate of its native Mongolia, (having) thick fur and underwool that (keeps) it warm in winter (and also) insulate against summer heat.

[/quote]
</p>

<p>The subject of the verb "keeps" is (technically by anaphoric way of "that") "thick fur and underwool," which is plural. Therefore, "keeps" ought to be "keep," also consistent with the plurally conjugated "insulate."</p>

<p>ahh i see now.. thank you so much</p>

<p>would have never thought of swum!</p>