A:
B:
C:
D:
A稀疏 B.最后 C.贫穷
①富饶____
②首先____
③茂密____
日本人20岁时,要举行“成人节”仪式,这时他们会穿上心爱的( )
①升高温度 ②加入催化剂 ③增大体系压强 ④增大反应物浓度.
_______ I walked into class, the teacher had started teaching already.