由于司钻缺乏警戒,以下哪些井涌原因是完全可以避免的?()
A.没灌满井眼
B.异常压力
C.井涌
D.气侵井液
参考答案:A
按照生物间的共同特征将其分类的学科被称为[ ]
A.发育学
B.生物学
C.分类学
D.演化论
用bring或take完成句子。
1. Please _____ these things to your parents.
2. Can you _____ some things to school? I need my hat and my English book.
3. Please _____ the jacket with you!
4. Can you _____ me your Chinese book?