某同学使用的显微镜有如下一些镜头可供选择（见下图），要使被观察的物体放大50倍，应选择的镜头为：
A．④和⑤
B．③和⑥
C．①和④
D．②和⑥
答案：C
幼儿急疹的主要临床表现，下列错误的是（）
A.突然发热较高
B.发热时精神、食欲均好
C.热退疹出
D.线状疹
E.皮疹呈玫瑰红色较小斑丘疹
The nurse plans to administer an injection of heparin to a client. Which of the following techniques for heparin administration is appropriate()
A. Selects a 1.5-inch, 21-gauge needle for the injection.
B. Makes the injection into the deltoid muscle.
C. Applies gentle pressure to the site for 5 to 10 seconds after the injection.
D. Aspirates with the plunger to check for entry into the blood vessel before injecting the heparin.
