1.D consider doing sth / help sb.do sth
2.C have difficulty (in) doing sth
3.B must have done表示对过去的肯定猜测
4.D choosing what to eat 是动名词作主语
1.D consider doing sth / help sb.do sth
2.C have difficulty (in) doing sth
3.B must have done表示对过去的肯定猜测
4.D choosing what to eat 是动名词作主语