第一信使（first messenger)

第一信使(first messenger)

A．in the final paragraph.

B．in the last but one paragraph.

C．in the first paragraph.

D．in the same paragraph.

A、Nervous system and digestive system

B、Endocrine system and respiratory System

C、Nervous system and endocrine system

D、Central nervous system and peripheral nervous system

E、The first messenger system and the second messenger system

A、Nervous system and endocrine system

B、Nervous system and digestive system

C、Endocrine system and respiratory System

D、Central nervous system and peripheral nervous system

E、The first messenger system and the second messenger system

Managers stopped the launch because of clouds near the pad at a critical point in the countdown. The minuscule 1 E-second launch window left no time to try again.

NASA hopes to try again early on Tuesday.

Messenger is set to begin a 4. 9 billion mile journey to orbit the planet Mercury and collect data on the planet's geology and atmospheric composition. It will be the first spacecraft to visit the planet since Mariner 10 whizzed by three times in 1974 and 1975. It will also be the first spacecraft ever to orbit the planet.

Launch controllers have until Aug. 14 to launch the spacecraft. After that, planetary alignment issues will postpone the launch for about a year. Upcoming launch opportunities will also have extraordinarily short launch windows.

The Messenger spacecraft was originally scheduled to be launched on ______.

A．Monday

B．Sunday

C．Tuesday

D．Wednesday

听力原文：News Item Two

Bad weather forced mission managers to postpone launching NASA's Messenger spacecraft on a Boeing Delta 2 rocket early on Monday,

Managers stopped the launch because of clouds near the pad at a critical point in the countdown. The minuscule 12-second launch window left no time to try again,

NASA hopes to try again early on Tuesday.

Messenger is set to begin a 4. 9 billion mile journey to orbit the planet Mercury and collect data on the planet's geology and atmospheric composition.It will be the first spacecraft to visit the planet since Mariner 10 whizzed by three times in 1974 and 1975. It will also be the first spacecraft ever to orbit the planet.

Launch controllers have until Aug. 14 to launch the spacecraft. After that, planetary alignment issues will postpone the launch for about a year. Upcoming launch opportunities will also have extraordinarily short launch windows.

The Messenger spacecraft was originally scheduled to be launched on _________.

A．Monday

B．Sunday

C．Tuesday

D．Wednesday

第二信使(second messenger)

继发性主动转运(second messenger)

A.受体

B.基因

C.激素

D.蛋白激酶