she warns us to be careful when the traffic is heavy.同义句转换

问题描述:

she warns us to be careful when the traffic is heavy.同义句转换
she warns us to be careful when ———— —————— —————— ——————
traffic

正确答案应该是:
there is too much
她提醒我们当交通非常繁忙时要特别小心