【单选题】Before Sept. 11, the U.S. Congress had been unable to pass stricter immigration laws because.
A.
they might have kept away foreign students and cheap labor
B.
it was difficult to coordinate the efforts of the congressmen
C.
education and business circles cared little about national security
D.
resources were not available for their enforcement
【简答题】电荷的 形成电流,形成持续电流的条件是 和 。
【简答题】电荷的____形成电流。形成持续电流的条件是____和____。
【单选题】The mining industry in the U.S. became safer after the late 1960s because
A.
the U.S. Senate passed laws requiring federal mine inspections.
B.
the U.S. Congress passed laws requiring federal mine inspections.
C.
the U.S. health and safety officials passed laws requiring federal mine inspections.
D.
the U.S, mine companies passed laws requiring federal mine inspections.
【单选题】In 1642 and 1647, the Bay Colony passed laws requiring all parents to provide _____ education for their children.
【单选题】Before Sept 11, the U.S. Congress had been unable to pass stricter immigration laws be- cause______.
A.
they might have kept away foreign students and cheap labor.
B.
it was difficult to coordinate the efforts of the congressmen.
C.
education and business circles cared little about nation.
D.
resources were not available for their enforcement.
【单选题】Laws requiring computer companies to pay for recycling their products have been passed for the purpose of ( )
A.
urging them to design upgradeable equipment
B.
cutting down their costs of production
C.
reducing the number of computers to be produced
D.
encouraging them to advertise their products