【单选题】In this passage, how is the discussion of optimism and pessimism developed?
B.
By comparison and contrast.
【多选题】关于镉的测定,说法正确的是( )
A.
镉的测定方法包括火焰原子吸收光谱法,电感耦合等离子体发射光谱法,双硫腙分光光度法,阳极溶出伏安法等
D.
当水样环境基体复杂时,常选用石墨炉原子吸收光谱法测定。
【多选题】关于电感耦合等离子体发射光谱法说法正确的是
C.
根据特征谱线的存在与否,鉴别样品中是否含有某种元素
【单选题】How many renters maily talked in this passage?
【单选题】How many people are mentioned in this passage?
【单选题】How many examples are cited in this passage to illustrate that the emotions are associated with illness?
【单选题】What does the author mainly discuss in this passage?
A.
How to avoid car crash.
B.
How to educate children properly.
C.
How to design safer baby equipment.
D.
How to properly secure children in the car.
【单选题】How many factors are mentioned in this passage influencing the Canadian economic contraction?