制动不足时（）或管路、加力泵有漏气现象可能造成的。
参考答案：制动气压低
A big company was built in our city in 2011, ______ a lot of job opportunities for the unemployed. [ ]
A. to create
B. created
C. creating
D. having created
电子邮件不是计算机病毒传播的一种途径。
