As the housing crisis mushroomed , the rating agencies downgraded dozens of securities .
随着住房危机不断扩大,评级机构下调了诸多证券的评级。
Private schools offering supplementary english tuition have mushroomed .
提供额外的英语教学的私立学校如雨后春笋般涌现。
Experts say missteps included a failure to address the problem fully in the early days ; the company 's dogged persistence in sticking to an early explanation that proved deeply flawed ; and misplaced priorities as the crisis mushroomed .