Researchers at recently concluded that a compound in green tea 17 the growth of cancer cells.
答案：(B) slows down
【句型】slow down 固定片語動詞「減緩」；looks after（照顧）、takes over（接管）、turns out（結果是）都不合。
slow down 你腦中的畫面大概是車子減速、或人放慢腳步，都是「自己慢下來」。這裡它是及物用法：後面直接接受詞 the growth of cancer cells，意思是「使……變慢、減緩」（劍橋詞典 slow down 詞條同時收不及物與及物兩種用法）。同一個片語，主詞從「自己慢下來」換成「讓別的東西慢下來」，中文就得從「減速」改成「減緩」。
分兩步。第一步看結構：空格後面有受詞 the growth，所以空格必須放得下受詞；四個選項在這一步都還過得去，刷不掉人。第二步看語意方向：整段從第一句 What is so special about green tea? 開始就在講綠茶的好處，緊接著下一句還說它 helpful，所以綠茶對癌細胞生長只可能是「壓下去」，不會是中性或正面的描述。這一格鑑別度 63，相當高，分開的正是「有沒有順著整段的正負方向讀」——只盯著空格那一句，四個片語塞進去文法都不會壞；把整段的方向讀進來，答案就只剩一個。
looks after 是「照顧」，主詞通常是人，「照顧癌細胞的生長」與全文方向完全相反。takes over 是「接管、接手」，需要有前一個負責的人或單位被接替，文中沒有這樣的對象。turns out 常見的用法是 turn out to be（結果是……）或後面接 that 子句，它不會直接接一個「生長」當受詞。
slow down（減緩、使變慢）、speed up（加快）、the growth of（……的生長）、cancer cells（癌細胞）、look after（照顧）、take over（接管）。
What is so special about green tea? The Chinese and Indians 16 it for at least 4,000 years to treat everything from headache to depression. Researchers at recently concluded that a compound in green tea 17 the growth of cancer cells. Green tea is also helpful 18 infection and damaged immune function. The secret power of green tea is its richness in a powerful anti-oxidant.
Green tea and black tea come from the same plant. Their 19 is in the processing. Green tea is dried but not fermented, and this shorter processing gives it a lighter flavor than black tea. It also helps retain the tea's beneficial chemicals. That is 20 green tea is so good for health.
The only reported negative effect of drinking green tea is a possible allergic reaction and insomnia due to the caffeine it contains.