What was one of the challenges Dr. Salk faced in his attempt to create a polio vaccine? (10 points)
a
b
Dr. Salk did not have enough money to pay for his research and supplies.
Dr. Salk had to create one vaccine that was effective against three different viruses.
Dr. Salk had to convince government officials to allow him to test the vaccine.
Dr. Salk's idea for a vaccine was not supported by other scientists and physicians,
d
Question 4 (10 points)
Read the entry on Jonas Salk from Compton's Encyclopedia/The Britannica School Edition, and answer the
Compton's Encyclopedia

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on the low like i frrl frrl dunno jitt

whats the passage

explanation:

you have no answers to choose

a complex sentence consists of an independent clause and one or more dependent clauses.  

to write complex sentences, we must use subordinating conjunctions.  

all the complex sentences begin with a subordinating conjunction and when it occurs, a comma must be place at the end of the dependent clause. on the contrary, if the sentence begins with an independent clause, then no comma is used.

after  

although  

as  

because  

before  

if  

since  

when  

for example,  

after she won the competition, she became very popular.  

although my father was hurt, he continued fighting for his rights.  

as all of you got a ten, you will be able to leave early today.  

before he went to the war, he asked his parents to bless him.  

if it is cold, i won’t go out.  

since you didn’t bring the homework, you will get low grades.  

when it is hot in the town, everyone goes to the beach.