The park gates ______ at 10:00 every evening.
A：lock
B：locked
C：are locked
D：were locked
能作为监测空气污染程度的指示植物（ ）
If you could give your younger self one piece of advice, what would you say?
要求：（1）作出回答并说出理由；（2）词数不少于60。
