One of the cornfields involved in the studies had an area of 2.5 hectares. In Study 2, how many kg N was added to that field as fertilizer N ?

A．60 kg N

B．100 kg N

C．240 kg N

D．300 kg N

[单选题]For nearly 17 yearsDavid Cope has worked as one of the Tower of London's ye

[单选题]For nearly 17 yearsDavid Cope has worked as one of the Tower of London's ye

[单选题]For nearly 17 yearsDavid Cope has worked as one of the Tower of London's ye

[单选题]For nearly 17 yearsDavid Cope has worked as one of the Tower of London's ye

[单选题]For nearly 17 yearsDavid Cope has worked as one of the Tower of London's ye

[单选题]For nearly 17 yearsDavid Cope has worked as one of the Tower of London's ye

[单选题]For nearly 17 yearsDavid Cope has worked as one of the Tower of London's ye

[单选题]For nearly 17 yearsDavid Cope has worked as one of the Tower of London's ye

[单选题]For nearly 17 yearsDavid Cope has worked as one of the Tower of London's ye

[单选题]For nearly 17 yearsDavid Cope has worked as one of the Tower of London's ye