6. At present the number of bone marrow donors in mainland China is ____.
6． D。分析：利用“the number of bone marrow donors 和mainland”作為答案線索，這樣發(fā)現(xiàn)答案相關(guān)句：(第3段)..compared fewer than 30,000 donors among mainland China’s 1.3 billion people, the newspaper said. (第4段) China needs a pool of at least 100,000 donors but testing them would cost..30，000/100，000 = 1/3， 因此判斷D是答案。
A．a(chǎn)bout one percent of the total population
B．to be responsible for childhood leukemia
C an urgent and tough task to be accomplished
E an expensive cost to be paid
7. Some solvents and building materials are considered ____.
7． B。分析：consider 后通常跟to 或as ，因此判斷B是答案。
A．a(chǎn)bout one percent of the total population
C an urgent and tough task to be accomplished
E an expensive cost to be paid
8. Obviously, recruiting voluntary bone marrow donors in mainland China is ___.
8． C。分析：根據(jù)搭配含義（很明顯，中國的大陸招募骨髓移植自愿者是一項(xiàng)緊迫而艱巨的任務(wù)）判斷C合適。
6． D。分析：利用“the number of bone marrow donors 和mainland”作為答案線索，這樣發(fā)現(xiàn)答案相關(guān)句：(第3段)..compared fewer than 30,000 donors among mainland China’s 1.3 billion people, the newspaper said. (第4段) China needs a pool of at least 100,000 donors but testing them would cost..30，000/100，000 = 1/3， 因此判斷D是答案。
A．a(chǎn)bout one percent of the total population
B．to be responsible for childhood leukemia
C an urgent and tough task to be accomplished
E an expensive cost to be paid
7. Some solvents and building materials are considered ____.
7． B。分析：consider 后通常跟to 或as ，因此判斷B是答案。
A．a(chǎn)bout one percent of the total population
C an urgent and tough task to be accomplished
E an expensive cost to be paid
8. Obviously, recruiting voluntary bone marrow donors in mainland China is ___.
8． C。分析：根據(jù)搭配含義（很明顯，中國的大陸招募骨髓移植自愿者是一項(xiàng)緊迫而艱巨的任務(wù)）判斷C合適。