问题
改错题
改错。
( ) 1. How much pens are there in your bag? _______________
A B C
( ) 2. — What are these? — They're box. _______________
A B C
( ) 3. — Where's Tom's picture? — It's on wall. _______________
A B C
( ) 4. — What's day is it today? — It's Tuesday. _______________
A B C
( ) 5. The cat on the tree is small. _______________
A B C
答案
1. A-many 2. C-boxes 3. C-on the wall 4. A-What 5. B-in
可知，一台在额定转速下工作的水泵，随着其工作流量的减小，比转速ns将（）。