已知1mol白磷变成1mol红磷放出18.39kJ的热量。下列两个方程式:
4P(白磷,s)+ 5O2(g)= 2P2O5(s);△H1
4P(红磷,s)+ 5O2(g)= 2P2O5(s);△H2
则△H1和△H2的关系正确的是( )
| A.△H1 =△H2 | B.△H1>△H2 |
| C.△H1<△H2 | D.不能确定 |
What I need is_____ book that contains ______ABC of oil painting.
| A.a; 不填 | B.the; 不填 | C.the; an | D.a ; the |
Jenny nearly missed the flight______ doing too much shopping.
| A.as a result of | B.on top of | C.in front of | D.in need of |
The CDs are on sale! Buy one and you get ______ completely free.
| A.other | B.others | C.one | D.ones ks |
I’m sure that your letter will get______ attention. They know you’re waiting for the reply. 
| A.continued | B.immediate | C.careful | D.general |
All the dishes in this menu, ______ otherwise stated, will serve two to three people. 
| A.as | B.if | C.though | D.unless |