1. Growing up can be difficult.
Growing up 是动名词作主语。被动形式为being done. Sb/sb’s doing sth 是动名词的复合结构，在句中作主语或宾语。
① ______ the meeting himself gave them a great deal of encouragement.
A. The president will attend B. The president to attend
C. The president attended D. The president’s attending
