一般情况下，每台锅炉至少应装设几个彼此独立的水位表（）
A.2
B.3
C.4
参考答案：A
He’s aiming ________a prize. That is why he puts his heart ________ his work.
A．at; of
B．to; off
C．for; away
D．at; into
百粒重测定应随机数取试验样品10个重复，每个重复100粒。
