18. Deserts and high mountains have always been a ________ to the movement of people from place to place.
A: barrier
B: fence
C: prevention
D: jam
A: barrier
B: fence
C: prevention
D: jam
举一反三
- Deserts and high mountains have always been a ________ to the movement of people from place to place. A: barrier B: fence C: prevention D: jam
- Deserts and high mountains have always been a ___to the movement of people from place to place.<br/>____ A: barrier B: fence C: prevention D: jam
- Deserts and high mountains have always been a ______ to the movement of people from place to place. A: A) barrier B: B) fence C: C) prevention D: D) jam
- Deserts and high mountains have always been a ________ to the movement of people from place to place.
- Directions： Choose the best answer from the four choices marked A, B, C and D.The mountains form a natural _________between the two countries. A: prevention B: obstruction C: barrier D: jam