We found the trees planted already.
We found many people planting trees there.
I saw him go into the dining room.
1．To learn English well，we should find opportunities to hear English ________ as much as we can.
C．spoken D．to speak
2．Jenny hopes that Mr. Smith will suggest a good way to have her written English________in a short period.
C．to improve D．improve
解析 本题考查非谓语动词。have在此处为使役动词，表示"使，让"，后可接do，doing或done作宾补，宾语her written English与improve之间为动宾关系，故应用过去分词作宾补。
3．He is very popular among his students as he always tries to make them________in his lectures.
C．interest D．to interest
解析 make them interested in中的them指代students，故用interested，表示"对......感兴趣"。
4．John received an invitation to dinner, and with his work ________， he gladly accepted it.
C．having finished D．was finished
5．Laws that punish parents for their little children's actions against laws get parents________.
A．worried B．to worry