A:x≤2
B:x≤2且x≠1
C:x≥2
D:x≥1
科学探究的一般步骤顺序是( )
①出问题
②制定计划
③出假设
④施计划
⑤得出结论
⑥表达与交流
-I didn't hear you come just now.
-That's good. We tried __________ any noise, for you were sleeping.