閱讀下面短文，根據(jù)語(yǔ)境、音標(biāo)或所給單詞的提示，在每個(gè)空格內(nèi)填入一個(gè)恰當(dāng)?shù)脑~，要求所填的詞意義準(zhǔn)確，形式正確，使短文意思完整、行文連貫。
   Elephants are the（1）

largest

largest

（large） animals on land.For a long time，they are helpful.They carry big trees，take people （2）

from

from

one place to another.And they are even（3）

useful

useful

/'ju?sfl/ in wars.
   Some people think it's not easy to hurt an elephant because its skin（皮膚） is（4）

thick

thick

/θ?k/ and hard.In fact，that's wrong.Sometimes，a needle（針） can also be very（5）

dangerous

dangerous

（danger） for the elephant.
   People say elephants are（6）

afraid

afraid

of mice.This is wrong，too.In fact，elephants have very poor eyesight，so they usually cannot see a mouse even if one comes very close to them.If a person has a good memory，people will say that he has an elephant memory（記憶）.（7）

However

However

，/ha??ev?（r）/，up to now，no study shows that elephants have a better memory（8）

than

than

other animals.
   People also believe that when it is time for elephants to die，they will hide（9）

themselves

themselves

（ they） in a so-called "elephant graveyard".Often，hunters try to find such places to get ivories（象牙），but few people really find places like that.In fact，when elephants are old or get sick，they will stay in deep and secret caves（秘密洞穴）（10）

until

until

they get better or die.