diff --git a/judger/Dockerfile b/judger/Dockerfile
index 73fd52b..745c543 100644
--- a/judger/Dockerfile
+++ b/judger/Dockerfile
@@ -1,4 +1,4 @@
-FROM ubuntu:18.04
+FROM ubuntu:20.04
 
 ARG CLONE_ADDFLAG
 
diff --git a/judger/install.sh b/judger/install.sh
index c6bd61d..ac45d54 100644
--- a/judger/install.sh
+++ b/judger/install.sh
@@ -8,6 +8,10 @@ getAptPackage(){
 
 setJudgeConf(){
     printf "\n\n==> Setting judger files\n"
+    #specify environment
+    cat > /etc/environment <<UOJEOF
+PATH="/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
+UOJEOF
     #Add judger user
     adduser judger --gecos "" --disabled-password
     #Set uoj_data path
diff --git a/judger/uoj_judger/run/run_program_conf.h b/judger/uoj_judger/run/run_program_conf.h
index 461d86b..68cf76e 100644
--- a/judger/uoj_judger/run/run_program_conf.h
+++ b/judger/uoj_judger/run/run_program_conf.h
@@ -193,6 +193,7 @@ int syscall_max_cnt_list_default[][2] = {
 	{__NR_write         , -1},
 	{__NR_readv         , -1},
 	{__NR_writev        , -1},
+	{__NR_pread64       , -1},
 	{__NR_open          , -1},
 	{__NR_unlink        , -1},
 	{__NR_close         , -1},
@@ -395,7 +396,7 @@ void init_conf(const RunProgramConfig &config) {
 		statable_file_name_set.insert("/usr/bin");
 		statable_file_name_set.insert("/usr/lib");
 		# ifdef UOJ_JUDGER_BASESYSTEM_UBUNTU1804
-		statable_file_name_set.insert("/usr/lib/python36.zip");
+		statable_file_name_set.insert("/usr/lib/python38.zip");
 		# endif
 	} else if (config.type == "java8") {
 		syscall_max_cnt[__NR_gettid         ] = -1;
@@ -408,6 +409,7 @@ void init_conf(const RunProgramConfig &config) {
 		syscall_max_cnt[__NR_clone          ] = 13;
 
 		syscall_max_cnt[__NR_getdents       ] = 4;
+		syscall_max_cnt[__NR_getdents64     ] = 4;
 
 		syscall_max_cnt[__NR_clock_getres   ] = 2;
 
@@ -455,6 +457,7 @@ void init_conf(const RunProgramConfig &config) {
 		syscall_max_cnt[__NR_clone          ] = 14;
 
 		syscall_max_cnt[__NR_getdents       ] = 4;
+		syscall_max_cnt[__NR_getdents64     ] = 4;
 
 		syscall_max_cnt[__NR_clock_getres   ] = 2;
 
@@ -474,6 +477,7 @@ void init_conf(const RunProgramConfig &config) {
 		syscall_max_cnt[__NR_pread64        ] = -1;
 		syscall_max_cnt[__NR_prctl          ] = -1;
 		syscall_max_cnt[__NR_nanosleep      ] = -1;
+		syscall_max_cnt[__NR_clock_nanosleep] = -1;
 		# endif
 
 		syscall_should_soft_ban[__NR_socket   ] = true;
@@ -518,6 +522,7 @@ void init_conf(const RunProgramConfig &config) {
 
 		syscall_max_cnt[__NR_setrlimit      ] = -1;
 		syscall_max_cnt[__NR_pipe           ] = -1;
+		syscall_max_cnt[__NR_pipe2           ] = -1;
 
 		syscall_max_cnt[__NR_getdents64     ] = -1;
 		syscall_max_cnt[__NR_getdents       ] = -1;
@@ -544,6 +549,7 @@ void init_conf(const RunProgramConfig &config) {
 		syscall_max_cnt[__NR_pread64        ] = -1;
 		syscall_max_cnt[__NR_prctl          ] = -1;
 		syscall_max_cnt[__NR_nanosleep      ] = -1;
+		syscall_max_cnt[__NR_clock_nanosleep] = -1;
 		syscall_max_cnt[__NR_socketpair     ] = -1;
 		# endif
 
diff --git a/web/app/controllers/faq.php b/web/app/controllers/faq.php
index 538c4f1..c404e07 100644
--- a/web/app/controllers/faq.php
+++ b/web/app/controllers/faq.php
@@ -47,13 +47,13 @@
 			</div>
 			<div id="collapseThree" class="collapse">
 				<div class="card-body">
-					<p>默认的测评环境是 Ubuntu Linux 18.04 LTS x64。</p>
-					<p>C的编译器是 gcc 7.4.0，编译命令：<code>gcc code.c -o code -lm -O2 -DONLINE_JUDGE</code>。</p>
-					<p>C++的编译器是 g++ 7.4.0，编译命令：<code>g++ code.cpp -o code -lm -O2 -DONLINE_JUDGE</code>。如果选择C++11会在编译命令后面添加<code>-std=c++11</code>。</p>
-					<p>Java8的JDK版本是 openjdk 1.8.0_222，编译命令：<code>javac code.java</code>。</p>
-					<p>Java11的JDK版本是 openjdk 11.0.4，编译命令：<code>javac code.java</code>。</p>
+					<p>默认的测评环境是 Ubuntu Linux 20.04 LTS x64。</p>
+					<p>C的编译器是 gcc 9.4.0，编译命令：<code>gcc code.c -o code -lm -O2 -DONLINE_JUDGE</code>。</p>
+					<p>C++的编译器是 g++ 9.4.0，编译命令：<code>g++ code.cpp -o code -lm -O2 -DONLINE_JUDGE</code>。如果选择C++11会在编译命令后面添加<code>-std=c++11</code>。</p>
+					<p>Java8的JDK版本是 openjdk 1.8.0_312，编译命令：<code>javac code.java</code>。</p>
+					<p>Java11的JDK版本是 openjdk 11.0.14，编译命令：<code>javac code.java</code>。</p>
 					<p>Pascal的编译器是 fpc 3.0.4，编译命令：<code>fpc code.pas -O2</code>。</p>
-					<p>Python会先编译为优化过的字节码<samp>.pyo</samp>文件。支持的Python版本分别为Python 2.7和3.6。</p>
+					<p>Python会先编译为优化过的字节码<samp>.pyo</samp>文件。支持的Python版本分别为Python 2.7和3.8。</p>
 				</div>
 			</div>
 		</div>