38=2，sin60°=32．
∴无理数是：π，sin60°共2个．
故选B．
根据句意从括号中选择恰当的介词填空
1. I go to school __________(at / on) 7:30 every morning.
2. The doctor would like to meet her __________(between / among) 8:00 and 9:00 tomorrow morning.
3. -When did Hong Kong return to China?
-__________(In / On) July 1st, 1997.
4. In the West, there is lots of excitement __________(in / on) Christmas morning when children get up
very early to open their presents.
5. The Smiths have lived in China __________ (for / since) five years.
若兰先生选择教育保险，则投资年限通常最高为( )年。
A．(A) 20
B．(B) 18
C．(C) 15
D．(D) 10
