作物病毒的诊断方法有田间观察和()两种。
参考答案:室内鉴定
Sam _______ some knowledge of the computer just by watching others working on it. [ ]
A. brought up
B. looked up
C. picked up
D. set up
在烹调蔬菜时,下列哪种做法易使水溶性维生素遭破坏()
A.尽量保持植株完整
B.先洗后切
C.急火快炒
D.适量加些醋
E.下锅前用冷水浸泡,开水烫,挤去汁液