D.for their resistance to plant diseases
答案：A
49.For the seed bank project to be successful，the most important factor is probably______________.
A.constructing tight airlocks
B. maintaining high security
C.keeping freezing temperatures
D.storing large quantities of seeds
答案：B
50.Which of the following statements is true?
A.The Norwegian vault models after existing seed banks.
B.The Spitsbergen seed bank is expected to last 10,006 years.
C. The existing seed banks have potential problems.
D.The UN financed the Spitsbergen seed bank.
答案：C
Passage Five
Probably the hardest part of setting goals is the first step of actually deciding to take action!The first barrier facing most people is the incorrect assumption that goals are only for business
people.The reality is everyone sets goals mentally throughout the day.There are always occasions
