诊断冷球蛋白血症时多选用()
A.冷凝集试验
B.嗜异性凝集试验
C.冷球蛋白检测试验
D.本周蛋白测定试验
E.以上均可选用
参考答案:C
人们常说,菠菜中含有丰富的铁质,这里的“铁质”指的是( )
A.分子
B.原子
C.元素
D.单质
I'm tired out. I stayed up the whole night, ______ for my midterm math exam. [ ]
A. studying
B. to study
C. to be studying
D. studied