The 2nd order reaction must be a bimolercular reaction.

The differential equation of a 2nd order C-T LTI system isand the initial state includes,. Then the zero-input response is ()

A、

B、

C、

D、

The differential equation of a 2nd order C-T LTI system isthen the form of the impulse response of the systemis ().

A、

B、

C、

D、

A、No relationship

B、have some relationship with the concentration

C、is proportion to the reactants concentration

D、It is depends on different conditions.

As you have seen, the value of nation's currency is a ___ of its economy.

A、reaction

B、response

C、reflection

D、revelation

The best choice for the title of the passage would be ______.

A．The Thirties in Art. Reaction and Rebellion

B．America in the Thirties: A Changing Time

C．Thomas Hart Benton and Regionalism

D．American Art. Appeal and Diversity

Small businesses join together!

Small businesses are being invited to join Smallbook Business Alliance (SBA). The Alliance, (29) ... currently has more than 70 members, was launched four years ago in order (30) ... support local businesses.

SBA President, Helen Smith, said: 'SBA can make (31) ... real difference to small firms. By (32) ... real business experiences, companies find they are in a better position to deal (33) ... the challenges facing them.'

Informal meetings (34) ... held for business owners twice a month. In addition to (35) .... there are a (36) ... formal events organised each year by the SBA, with a guest speaker present at (37) ... event.

The next meeting takes place on 21st April. The topic is the business fair (38) ... to take plaoe in the city in July. Helen Smith said: 'We (39) ... it to be a very popular event indeed. We've sold over 120 tickets (40) .... and it's only 2nd April today.

(29)

A．which

B．who

C．whose

A.0

B.n

C.2n

D.4n

A.n, 2n+1

B.n+1,2n+2

C.n,2n

D.n+1,2n