There are a number of（）on the desk.

A:dictionary
  B:dictionarys
  C:dictionaries

(A number of) endangered (species) (increases) every year and natural (resources disappear).

A:A number of B:species C:representative D:resigned disappear

(A number) of these (who) (study) engineering is improving (steadily).

A:A number B:who C:study D:steadily

There was a (number) of children on the playground.

A:class B:great crowd C:small group D:line

There was a (number) of children on the playground.

A:class B:great crowd C:small group D:line

下列运算符函数中，肯定不属于类Number的成员函数的是______。

A:Number operator+(Number); B:Number operator-(Number); C:Number operator*(int); D:Number operator/(Number,Number);