每两个月一次的

Plants were hydroponically grown in solutions containing 3 mM Ca(NO3)2 or 3 mM NH4NO3 as nitrogen source. Mature plants were harvested eight times in one day at a 3 hr. interval from 8:00PM Aug. 12 to 5:00PM Aug. 13. Diurnal variations of the shoot nitrate content were observed in either Ca(NO3)2 or NH4NO3 treatment. Shoot nitrate content of Ca(NO3)2 treated plants were higher than those treated with NH4NO3 at every harvest. The average shoot nitrate content of lettuce with Ca(NO3)2 was 0.68% of the dry weight, and it was 0.29% for the NH4NO3 treated lettuce. The fresh weight of the NH4NO3 treated lettuce were 1.43 or 1.2 fold heavier than those with Ca(NO3)2 treatment for shoot or root respectively.

R36品种以3mM硝酸钙(6mM N)或3mM硝酸铵(6mM N)处理，於8月12日下午8点开始采收，每隔3小时采收一次，采收至8月13日下午5点。3mM硝酸钙与3硝酸铵两种养液处理的地上部硝态氮含量皆有日变化，而且在8个采收时间，3mM硝酸钙养液处理的地上部硝态含量皆高於3mM硝酸铵处理。8个采收时间的硝态氮含量平均，3mM硝酸钙养液为乾物含量的0.68%，而3mM硝酸铵处理为0.29%。3mM硝酸铵养液处理的地上部与根部鲜重分别为3mM硝酸钙处理的1.43倍及1.2倍。

They weren't aggressive, but I yelled and threw a rock in their direction to get them off the trail and away from me, just in case.

他们没有侵略性，但我大喊，并在他们的方向扔石头让他们过的线索，远离我，以防万一。

In slot 2 in your bag put wrapping paper, quantity does not matter in this case.

在你的书包里槽2把包装纸、数量无关紧要。