对于石油中的烷烃，常温常压下，当碳原子个数多于（）时，呈固态。
A.3
B.5
C.10
D.16
参考答案：D
管道中使用的法兰有哪几种？
A sum of $200,000 from a certain estate was divided among a spouse and three children. How much of the estate did the youngest child receive ？（）
(1)The spouse received of the sum from the estate, and tile oldest child received of the remainder.
(2)Each of the two younger children received $12.500 more than the oldest child and $62,500 less than the spouse.
A．条件(1)充分，但条件(2)不充分．
B．条件(2)充分，但条件(1)不充分．
C．条件(1)和(2)单独都不充分，但条件(1)和条件(2)联合起来充分．
D．条件(1)充分，条件(2)也充分．
E．条件(1)和条件(2)单独都不充分，条件(1)和条件(2)联合起来也不充分．
of the sum from the estate, and tile oldest child received of 
the remainder.