下列化学表达方式错误的是( )
A.中子数为20的氯原子:37Cl | B.S2-的结构示意图:![]() |
C.CCl4的电子式:![]() |
D.2-甲基丁烷的结构简式:![]() |
Progress______ so far very good and we are sure that the work will be finished on time.
A.was | B.had been | C.has been | D.will be |
Charles was alone at home, with_______ looking after him.
A.someone | B.anyone | C.not one | D.no one |
It is often ______ that human beings are naturally equipped to speak.
A.said | B.to say | C.saying | D.being said |
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 |