2993. Catalyst is substance used to change the speed or rate of a chemical action without being chemically changed itself

A. Our earth is in danger because of serious pollution. We must prevent chemicals from polluting our earth.

B. Our earth is in danger because of serious pollution. We must keep chemicals to polluting our earth.

C. Our earth is in danger because of serious pollution. We must ask chemicals for polluting our earth.

A. The slow moving and high pressure air from the turbine is fed into the combustor or burner where it is mixed with a highly flammable fuel and ignited.

B. The slow moving, high pressure air from the compressor is fed with the combustor or burner where it is mixed with a highly flammable fuel and ignited.

C. The slow moving, high pressure air from the compressor is fed into the combustor or burner where it is mixed with a highly flammable fuel and ignited.

A. 如果能够启动发动机,继续完成当前测试

B. 如果能够启动发动机,执行适用的测试

C. 如果能够启动发动机,执行所有测试

A. The closed door prevents airflow from entering the compartment and may cause death because of no air to breathe.

B. When the access plate is closed, the lack of ventilation of the compartment brings a risk of suffering injury.

C. If you close the opening, the airflow can not enter into the compartment and creates a risk of jam.

A. 飞机内部连接外部电源和飞机电气系统的系统。

B. 飞机整体连接外部电源和飞机电气系统的系统。

C. 飞机外部连接内部电源和飞机电气系统的系统。

A. Do the tightening procedure.

B. Do the loosening procedure.

C. Do the strengthening procedure.

A. Make the airplane fall.

B. Ground the airplane.

C. Touch the airplane.

A. 当你使用产生火花的电气设备时,请带上护目镜。

B. 当你使用产生火花的电气设备时,请带上面罩。

C. 当你使用产生火花的电气设备时,请穿上防护服。

A. The external diameter must be concentric to the internal diameter

B. The outer radius and the inner radius must be suitable.

C. The exterior radius must be installed on a common shaft with the interior radius.

A. 生产主管应根据工卡执行额外的任务。

B. 生产主管应根据任务设计的要求执行指定的任务。

C. 生产主管应根据工卡执行指定的任务。