The inclination of the Leaning Tower of Pisa in Italy is a ____ problem. A: stability B: deformation C: seepage D: others

（ ） refers to the channel on a steep slope, and it is also known as the suspended ditch. A: Chute B: side ditches C: seepage ditch D: underdrain

It is generally believed that the appropriate daily seepage amount for high-yield rice fields is A: A. 35mm or more; B: B. 30～35mm; C: C. 10～15mm; D: D. 5mm or more.