根系从土壤吸收矿质元素的方式有两种：（）和（）
参考答案：通过土壤溶液得到、直接交换得到
Graves病浸润性突眼的病因是
A．眶内软组织水肿
B．眶内脂肪组织增生
C．精神过度紧张
D．眼球后有新生物
E．交感神经兴奋和眼外肌及上睑肌张力增高
I _____ to the party _____ at all possible, but I was fully occupied last night. [ ]
A. should have gone; were it
B. could go; if it had been
C. would go; it had been
D. could have gone; had it been
