（）运算符用来指明某个变量、标号或地址表达式的类型属性。
参考答案：PTR
Zhang Feng is a League member . He the League since 3 years ago.
A. joined B joined in C .has been in D .has joined in
关于多发性肌炎/皮肌炎预后的叙述，正确的是
A．严重的皮肌炎患者，肌酸激酶不升高者，预后较好
B．有呼吸肌受累者预后差
C．有吞咽困难者预后差
D．合并恶性肿瘤者预后差
E．早期诊断、对激素敏感者预后较好
