空气中液化石油气最高浓度低于（）%时，对人体健康无害。
A.0.1
B.0.5
C.1
D.1.5
参考答案：C
______children whose parents had died in the earthquake ____ sent to live with families in other cities.
A．A great number of; were
B．A great number of; was
C．The great number of; were
D．The great number of; was
类比思维
