sent disaster relief materials to help the flooded area in Taiwan Island.
答案： C
20．(2011青島聯合模擬)China’s new food law provides for a food recall system ________producers have to stop production if their food isn’t up to standards.
A．where B．that
C．when D．which
解析： 考查定語從句。句意為：中國新的食品法規定了食品召回製度，即如果食品達不到標準，生產者就必須停止生產。先行詞為a food recall system，定語從句為producers have to stop production if their food isn’t up to standards(in the food recall system)，故選A。
答案： A
21． Our teacher urges us to form a good habit of learning，________we think will benefit us in the long term.
A．what B．that
C．which D．who
解析： 本題考查定語從句。本題屬於非限製性定語從句，從句意可知關係代詞指代a good habit of learning，在從句中作主語，因此選擇which。
答案： C
22．(2011福建龍岩檢測)Remember that there is still one point________we must make clear at the conference tomorrow.
A．where B．why
C．when D．that
解析： 考查定語從句。解定語從句題的關鍵是：在主句中找出先行詞，該句的先行詞是one point，然後把先行詞“代入”從句中，判斷其在從句中的“地位”和“作用”，這裏先行詞在從句中作make clear的賓語，所以用關係代詞that/which引導定語從句並在從句中作賓語，據此選D項。
答案： D
23．She’s in a hopeless situation，________we will keep a very close eye on.
A．where B．when
C．which D．that
解析： 考查定語從句。定語從句的解題關鍵是：在主句中找出先行詞，該句的先行詞是a hopeless situation，然後把先行詞“代入”從句中，判斷其在從句中的“地位”和“作用”，此處關係詞在從句中作on的賓語，同時這裏又是非限製性定語從句，所以應該用關係代詞which，選C項。
答案： C
24．I admire my English teacher. I can remember very few occasions ________she stopped working because of ill health.
A．that B．when
C．where D．which
解析： 考查定語從句。根據語意“我記得她很少因生病而停止工作”可知，定語從句引導詞在從句中作狀語，故用when。
答案： B
25．(2011海南五校聯考)The moment________John will never forget is________Mr Smith gave him a lot of valuable advice on how to improve his writing.