凝胶层析中,有时溶质的Kd>1,其原因是()。
A.凝胶排斥
B.凝胶吸附
C.柱床过长
D.流速过低
参考答案:B
选出句子中的错误并改正。
( ) 1. This book look interesting. ___________________
A B C
( ) 2. He have already bought a new bike. ___________________
( ) 3. She's eating dinner while her mother is clean room. ___________________
( ) 4. It is get hot. ___________________
( ) 5. The apples is sweet, I think. ___________________
影响生态平衡的因素有( )。
A.物种改变
B.盲目开荒
C.资源利用不合理
D.环境污染
E.以上都是