<p>Please give an explanation for the answers. i got these wrong. </p>
<p>The bus would not have had [to take] the long detour [instead of] the main highway if the bridge [did not become] treacherous [in the aftermath of an ice storm]. </p>
<p>i put did not become</p>
<p>Despite research [on the diagnosis of] heart disease and the use of [increasingly] sophisticated technology [in its treatment], the condition of coronary arteries [is] still difficult to assess precisely. [no error]</p>
<p>i put in its treatment because it sounded ambiguous. </p>
<p>It was obvious that all the candidates had planned carefully for the televised debate, [for each] [answer to] the opening question showed evidence [of having been rehearsed]. [no error] </p>
<p>i put of having been rehearsed because it sounded awkward. </p>
<p>The seven-month-old baby was considered precocious [to her family] because she was [already able] to grasp tiny items [delicately] [between her thumb] and forefinger. [no error]</p>
<p>i put delicately because it was separated from the verb. </p>
<p>Although it may sound ludicrous to some, there is much truth [to it], as those who have experienced such failures can attest. </p>
<p>this one is supposed to be to this sentiment. I said as it is now. I don't understand this one.</p>