— _____ will your father return home? It's a long time since I saw him last time.
— Just in two days.
A:How long
B:How often
C:How soon
D:How old
喷施2,4﹣D对春砂仁保果和产量的影响
处理浓度(ppm)
幼果数(个)
收果数(个)
保果率(%)
增减产(克/米2)
5
232.7
123.3
52.9
+69.6
10
189.3
97.6
51.5
+5.5
15
160.0
75.3
47.0
﹣34.9
0
201.6
92.3
45.7
注:1ppm=0.0001%