问题
选择题
_______ advantages and disadvantages, Mr. Smith decided to leave the company and go to the west to try his fortune.
A．Having compared
B．Having balanced
C．Having observed
D．Having examined
答案
答案：B
考查非谓语动词以及词义辨析。句意：权衡利弊之后史密斯先生决定离开公司去西部淘金。Compare 比较， balance 权衡， observe 观察，examine 检查，现在分词的完成式表示分词动作发生在谓语动作之前且与句子主语为主谓关系。故选B
面大面积崩瓷露出金属底冠，上下颌修复体密合度均欠佳，口腔卫生情况差，牙龈充血水肿。
龈高度，增加对颌牙高度来建