5 单选 which of the following metals could be chose to increase the high temperature strength of alloy steel？

A、confide to sb.

B、stand by sb's side

C、lend sb. a sympathetic ear

D、console sb. through heartbreaks and disappointments

A、grunt

B、mumble

C、spout

D、roar

A、Research into why the growth rate of total production increased during the 1990s.

B、A theory of how consumers decide what to do.

C、An analysis of Dell Computer's share of the personal computer market.

D、Research on why interest rates were unusually high in the 1970s and early 1980s.

A. Wireless router

B. Unmanaged switch

C. Hub

D. Repeater

Which of the following terms could be applied to the simple definition "the energy of motion?

A.Electrical energy

B.Thermal energy

C.Potential energy

D.Kinetic energy

A、changeable

B、unpredictable

C、pleasant

D、settled

A、How many employees do you have ?

B、What is your company's line of business

C、What kind of products and services do your company provide ?

D、When was your company founded ?

A、Raising tuition.

B、Full enrollment.

C、National awareness and support.

D、Reduction of rising costs.

Which of the following conditions could contribute to the cracking of a diesel engine cylinder head?

A.Leaking seal ring

B.Insufficient heat transfer from the exhaust valves

C.Blocked cooling water passages to the head

D.Excessive scavenging air provided to the engine

A、suggest

B、assert

C、maintain

D、reject