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。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。