Agricultural experts say crop diversity is important to feed the（1）

increasing

increasing

（increase） population of our planet． They say having a large variety of plants also（2）

helps

helps

（help） to protect against possible crop diseases and future crises． But many experts say the number has decreased sharply during the past century．
    One of the world's （3）

largest

largest

（large） seed conservation projects has predicted further losses． The Millennium Seed Bank Partnership is warning that up to one hundred thousand plant species could （4）

permanently

permanently

（permanent） disappear． The rich collection of genes（5）

that/which

that/which

decide their qualities would disappear with them．
    Many experts blame climate change and loss of habitat， normal growth area， for damaging plant life． They say human（6）

activities

activities

（activity） and poorly planned， overly heavy use of land also are responsible． Modern business farming is responsible（7）

for

for

loss of farmers' traditional crop varieties． The "Green Revolution" of the twentieth century changed agriculture． Some experts say the use of modern commercial farming methods saved millions of people from（8）

starvation

starvation

（starve）． Farmers planted， watered， and fertilized their crops with the help of machines． They treated their fields with chemicals（9）

to control

to control

（control） diseases and insects． Harvests grew larger and higher quality，（10）

but/while/yet

but/while/yet

another result was that some traditional crops were lost． Damage to the environment over the past century makes people believe that crop diversity also suffered．