符合注射原则的是（）

A.按药液粘稠度选择注射器

B.皮肤消毒直径大于3cm

C.排气时不浪费药液

D.各种注射都应检查有无回血

E.药液在注射前临时抽取

The number of the people present at the concert ________ much smaller than expected. There ________ many tickets left.

A．was; was

B．were; was

C．were; were

D．was; were