学校附近的狭窄街道在放学时总是形成交通瓶颈。

The narrow street near the school always becomes a ___bottleneck when classes end.

高峰时段交通拥堵是城市通勤的主要瓶颈。

Traffic congestion during rush hour is the biggest ___bottleneck in urban commuting.

供应链中的运输问题成为了我们提高产量的瓶颈。

Transportation issues in the supply chain have become a major ___bottleneck in increasing our production.