托福考试

【单选题】While play is important at all levels of human development, （） takes on particular significance when children are five and six years old. 
A. it 
B. and 
C. which 
D. because it 

【分析解答题】thE FunDAmEntAl physiCAl (prinCiplE) oF photogrAphy is thAt (light FAlling) on thE grAins (oF CErtAin) insoluBlE silvEr sAlts proDuCEs smAll, (invisiBly) ChAngEs in thE grAins.

【单选题】 Which of the following is mentioned as the dominant theme in Roesen's painting
A．( Fertility
B．( Freedom
C．( Impermanence
D．( Abundance

【单选题】 The word "remarkable" in line 14 is closest in meaning to
A．( genuine
B．( permanent
C．( extraordinary
D．( continuous

【单选题】 The distinguishing feature of a fluid, in contrast to a solid, is the ease __________
A．( that a deformed fluid
B．( to deform a fluid
C．( when a fluid that is deformed
D．( with which a fluid may be deformed