对于北方带冻土块移栽的树木进行根系防冻保温处理后，早春土壤化冻时就要掀开保温材料，否则会影响根系正常生产。( )
参考答案：对
单词拼写。
1. They have a school t____________ every year.
2. August is the e____________ month of the year.
3. F____________ is the second month of the year.
4. —What's the d____________ today? —It's March 2nd.
5. S____________ 10th is Teachers' Day.
6. We come from China.We speak C____________.
7. December is the t____________ month of the year.
8. B____________ is the date of one's birth.
9. N____________ comes after October.
10. The Spring ____________ is important to every Chinese.
在腐蚀介质环境中使用的气瓶检验周期是（）.
A、每3年一次；
B、每2年一次；
C、每4年一次；
D、每6年一次.
