如果学校生源质量高，教师水平较好，不课改行也行。（）
参考答案：错
The news that a jet __________ Russian mountains killing 88 was one of the worst things I have known in the past five years.[ ]
A. crashed down
B. crashed into
C. met with
D. came across
防治介壳虫时为增加药效可在药剂中添加（）。
A、展着剂
B、分散剂
C、颗粒剂
