For a molecule with a center of symmetry, which is the correct statement about the vibration that has a symmetric relationship with the center of symmetry? A: Infrared invisible, Raman visible; B: Infrared visible, Raman invisible; C: Infrared invisible, Raman invisible; D: Infrared visible, Raman visible

Bats can build an infrared ( ) to help them navigate.

The accumulation of greenhouse gases (GHGs) causes global warming by letting sunlight into the atmosphere as _______. Then, when the earth re-radiates the heat back to space, the gases trap the energy in the form of outgoing ______. A: visible light, ultraviolet radiation B: infrared radiation, ultraviolet radiation C: ultraviolet radiation, infrared radiation D: infrared radiation, radio waves

以下属于电离辐射的是（） A: X-rays B: Radio wave C: Infrared D: Microwave

2. Greenhouse gases are the gases absorbs and emits radiant energy within the thermal infrared range, which cause the .

The cockpit is provided with _____ insulation. A: radio B: heat and sound C: infrared ray and ultraviolet ray D: sunlight

中国大学MOOC: So more of the outgoing infrared remains in the atmosphere. As a result the atmosphere heats up (8) ________.

What is one of two kinds of path recognition modules?(). A: CDC B: Infrared<br/>sensor C: DCC D: DCD

For breast cancer diagnosis, which of the following methods is the<br/>most effective? () A: Infrared B: Ultrasonic C: MRI D: Mammography

Will London's transport ______ cope with the extra traffic from the Olympic and Paralympic Games? A: infrastructure B: substructure C: restructure D: infrared