问题 问答题 简答题

怎样预防产生青头楞?

答案

参考答案:

(1)严格掌握播种深度,及时中耕培土。马铃薯播种期,要及时检查播种深度,控制过浅播种;垄作栽培要趟成“四方头大垄”,创造块茎在土壤中生长膨大的良好条件,避免块茎露出垄外见光变绿。

(2)避光作业,尤其是食用薯和加工业用原料薯在收获和运输过程中,随起收,随拣净,随覆盖或装袋,避免日光照射。在贮藏过程中,也要避免照明灯光长时间内对块茎照射。

单项选择题
单项选择题

阅读下面短文,从短文后各题所给的四个选项(A、B、C和D)中,选出可以填入空白处的最佳选项,并在答题卡上将该项涂黑。学科&网

Hundreds of people have formed impressions of you through that little device(装置) on your desk. And they’ve never actually   41   you. Everything they know about you   42   through this device, sometimes from hundreds of miles away.   43   they feel they can know you   44   from the sound of your voice. That’s how powerful the   45   is.

Powerful, yes, but not always   46  . For years I dealt with my travel agent only by phone. Rani, my faceless agent whom I’d never met   47  , got me rock-bottom prices on airfares, cars, and hotels. But her cold voice really   48   me. I sometimes wished to   49   another agent.

One morning, I had to   50   an immediate flight home for a family emergency. I ran into Rani’s office   51  . The woman sitting at the desk,   52   my madness, sympathetically jumped up. She gave me a   53   smile, nodded while listening patiently, and then printed out the   54   immediately. “What a wonderful lady!” I thought.

Rushing out   55   I called out over my shoulder, “By the way, what’s your name?” “I’m Rani,” she said. I turned around and saw a   56   woman with a big smile on her face waving to wish me a safe trip. I was   57  ! Why had I thought she was cold? Rani was, well, so   58  .

Sitting back in the car on the way to the airport, I figured it all out. Rani’s   59  ---her warm smile, her nods, her ‘I’m here for you’   60  ---were all silent signals that didn’t travel through wires.

51()

A. for the first time

B. at any time

C. from time to time

D. in good time