到20世纪末,人类发现和合成的物质已超过2000万种,但组成这些物质的基本元素只有( )
A.300多种
B.1000多种
C.2000多种
D.100多种
答案:D
Lily生病了,请你帮她选择该做的事(√)和不该做的事(×)。
( ) 1. Stay in bed.
( ) 2. Playing computer games.
( ) 3. See a doctor.
( ) 4. Drink more hot water.
( ) 5. Study hard and read many books.
( ) 6. Take some medicine.
( ) 7. Watch TV day and night.
( ) 8. Go on a trip.
( ) 9. Play with friends outside.
( ) 10. Have a good rest.
骨盆创伤后膀胱破裂的最好诊断方法是
A.膀胱镜检查B.静脉肾盂造影C.膀胱造影D.注入一定量的灌洗液不能全部抽出E.血尿