Questions

Gram is not a Plantation crop among the given options.

Plantation crops are known as cash crops. These crops are mostly grown at tropical and subtropical areas. These crops are grown for sale but not for local consumption. such crops include rubber, coffee, tea, various oil seeds, sugar cane,etc.

So, Gram is not a plantation crop.

Black surfaces are good emitters of heat. If the black surface is rough too, the emitting will be better. Shinning surfaces reflect black radiation . So if the black surface is also shining the effectiveness of emitting heat is lessened.

The US Congress consists of two bodies 

a) the Senate and   b) the House of Representatives. The Senate, composed of 100 members (two Senators from each State), is a powerful body and exercises a very real influence in national affairs.