潮汐河口航道治理一般采用（）两者相结合的手段进行。
A.炸礁与疏浚
B.筑坝与护岸
C.整治与疏浚
D.筑坝与疏浚
参考答案：C
Knowing how long the test would last, the students who finished ____ back and waited until the end of the exam.
A．settle
B．settled
C．settling
D．to settle
无偿发行
